Home
Videos uploaded by user “Khan Academy”
You Can Learn Anything
 
01:31
Khan Academy is on a mission to unlock the world's potential. Most people think their intelligence is fixed. The science says it’s not. It starts with knowing you can learn anything. Join the movement at http://khanacademy.org/youcanlearnanything. About Khan Academy Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything.
Views: 5989407 Khan Academy
John Legend: Success through effort
 
02:02
John Legend shares a personal story about overcoming early rejections in his career to get to where he is today. Join the You Can Learn Anything movement at www.khanacademy.org/YouCanLearnAnything
Views: 379353 Khan Academy
Frequency stability property short film | Computer Science | Khan Academy
 
02:09
Can you tell the difference between actions based upon flipping a coin and those based upon blind guessing or simulating randomness? This short video examines the frequency stability property. Watch the next lesson: https://www.khanacademy.org/computing/computer-science/cryptography/crypt/v/case-study-ww2-encryption-machines?utm_source=YT&utm_medium=Desc&utm_campaign=computerscience Missed the previous lesson? https://www.khanacademy.org/computing/computer-science/cryptography/crypt/v/one-time-pad?utm_source=YT&utm_medium=Desc&utm_campaign=computerscience Computer Science on Khan Academy: Learn select topics from computer science - algorithms (how we solve common problems in computer science and measure the efficiency of our solutions), cryptography (how we protect secret information), and information theory (how we encode and compress information). About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Computer Science channel: https://www.youtube.com/channel/UC8uHgAVBOy5h1fDsjQghWCw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 386928 Khan Academy
Interest rate swap 1 | Finance & Capital Markets | Khan Academy
 
03:51
The basic dynamic of an interest rate swap. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/interest-rate-swaps-tut/v/interest-rate-swap-2?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/credit-default-swaps-tut/v/financial-weapons-of-mass-destruction?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Interest is the basis of modern capital markets. Depending on whether you are lending or borrowing, it can be viewed as a return on an asset (lending) or the cost of capital (borrowing). This tutorial gives an introduction to this fundamental concept, including what it means to compound. It also gives a rule of thumb that might make it easy to do some rough interest calculations in your head. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 261700 Khan Academy
Pixar in a Box | Welcome to Pixar in a Box | Khan Academy
 
05:20
Watch the next lesson: https://www.khanacademy.org/partner-content/pixar/effects/particle/v/effects-overview?utm_source=YT&utm_medium=Desc&utm_campaign=computeranimation Computer Animation on Khan Academy: A collaboration between Pixar Animation Studios and Khan Academy. Sponsored by Disney. Questions/Feedback: [email protected] About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Computing Animation channel: https://www.youtube.com/channel/UCUj311Am0evWzQJcBsu4fvw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 1288324 Khan Academy
Arbitrage basics | Finance & Capital Markets | Khan Academy
 
02:51
Arbitrage Basics. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/put-call-options/v/put-call-parity-arbitrage-i?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/put-call-options/v/call-writer-payoff-diagram?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Options allow investors and speculators to hedge downside (or upside). It allows them to trade on a belief that prices will change a lot--just not clear about direction. It allows them to benefit in any market (with leverage) if they speculate correctly. This tutorial walks through option basics and even goes into some fairly sophisticated option mechanics. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 292623 Khan Academy
The Growth Mindset
 
03:07
Sal talks with Stanford Professor Carol Dweck about her research on the Growth Mindset. Join the You Can Learn Anything movement at www.khanacademy.org/YouCanLearnAnything
Views: 422159 Khan Academy
Treasury bond prices and yields | Stocks and bonds | Finance & Capital Markets | Khan Academy
 
03:47
Why yields go down when prices go up. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/stock-and-bonds/bonds-tutorial/v/annual-interest-varying-with-debt-maturity?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/stock-and-bonds/bonds-tutorial/v/relationship-between-bond-prices-and-interest-rates?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Both corporations and governments can borrow money by selling bonds. This tutorial explains how this works and how bond prices relate to interest rates. In general, understanding this not only helps you with your own investing, but gives you a lens on the entire global economy. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 242439 Khan Academy
Introduction to i and imaginary numbers | Imaginary and complex numbers | Precalculus | Khan Academy
 
05:20
Introduction to i and imaginary numbers Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/precalculus/imaginary_complex_precalc/i_precalc/e/imaginary_unit_powers?utm_source=YT&utm_medium=Desc&utm_campaign=Precalculus Watch the next lesson: https://www.khanacademy.org/math/precalculus/imaginary_complex_precalc/i_precalc/v/calculating-i-raised-to-arbitrary-exponents?utm_source=YT&utm_medium=Desc&utm_campaign=Precalculus Missed the previous lesson? https://www.khanacademy.org/math/precalculus/parametric_equations/polar_coor/v/polar-coordinates-3?utm_source=YT&utm_medium=Desc&utm_campaign=Precalculus Precalculus on Khan Academy: You may think that precalculus is simply the course you take before calculus. You would be right, of course, but that definition doesn't mean anything unless you have some knowledge of what calculus is. Let's keep it simple, shall we? Calculus is a conceptual framework which provides systematic techniques for solving problems. These problems are appropriately applicable to analytic geometry and algebra. Therefore....precalculus gives you the background for the mathematical concepts, problems, issues and techniques that appear in calculus, including trigonometry, functions, complex numbers, vectors, matrices, and others. There you have it ladies and gentlemen....an introduction to precalculus! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Precalculus channel: https://www.youtube.com/channel/UCBeHztHRWuVvnlwm20u2hNA?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 1003912 Khan Academy
Lac operon
 
11:05
Overview of gene regulation in the Lac operon. Discussion of CAP, cAMP, lac repressor and allolactose in regulation of lac operon.
Views: 356696 Khan Academy
Credit default swaps | Finance & Capital Markets | Khan Academy
 
10:57
Introduction to credit default swaps. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/credit-default-swaps-tut/v/credit-default-swaps-2?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/credit-default-swaps-tut/v/credit-default-swaps-cds-intro?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Interest is the basis of modern capital markets. Depending on whether you are lending or borrowing, it can be viewed as a return on an asset (lending) or the cost of capital (borrowing). This tutorial gives an introduction to this fundamental concept, including what it means to compound. It also gives a rule of thumb that might make it easy to do some rough interest calculations in your head. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 599752 Khan Academy
Growing your mind
 
03:05
Your mental abilities are not fixed. Sal explains how your brain grows when you struggle with problems. Abbreviated version of https://www.youtube.com/watch?v=GWSZ1DKjNzY.
Views: 716453 Khan Academy
Transfer pricing and tax havens | Taxes | Finance & Capital Markets | Khan Academy
 
06:47
How a corporation can set up a tax haven and use it through transfer pricing. Created by Sal Khan. Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/taxes-topic/corporate-taxation/v/is-limited-liability-or-double-taxation-fair?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: In exchange for being treated as a person-like-legal entity (and the limited liability this gives for its owners), most corporations pay taxes. This tutorial focuses on what corporations are, "double taxation" and a few ways that multinationals might try to get out of paying taxes. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 196244 Khan Academy
Anatomy of a neuron | Human anatomy and physiology | Health & Medicine | Khan Academy
 
06:13
Neurons (or nerve cells) are specialized cells that transmit and receive electrical signals in the body. Neurons are composed of three main parts: dendrites, a cell body, and an axon. Signals are received through the dendrites, travel to the cell body, and continue down the axon until they reach the synapse (the communication point between two neurons). Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/nervous-system-introduction/v/overview-of-neuron-structure?utm_source=YT&utm_medium=Desc&utm_campaign=healthandmedicine Missed the previous lesson? https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/nervous-system-introduction/v/introduction-to-neural-cell-types?utm_source=YT&utm_medium=Desc&utm_campaign=healthandmedicine Health & Medicine on Khan Academy: No organ quite symbolizes love like the heart. One reason may be that your heart helps you live, by moving ~5 liters (1.3 gallons) of blood through almost 100,000 kilometers (62,000 miles) of blood vessels every single minute! It has to do this all day, everyday, without ever taking a vacation! Now that is true love. Learn about how the heart works, how blood flows through the heart, where the blood goes after it leaves the heart, and what your heart is doing when it makes the sound “Lub Dub.” About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Health & Medicine channel: https://www.youtube.com/channel/UC1RAowgA3q8Gl7exSWJuDEw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 1150667 Khan Academy
Introduction to chirality | Stereochemistry | Organic chemistry | Khan Academy
 
06:46
Introduction to chirality (handedness), and how chirality is related to the groups bonded to a central carbon. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/organic-chemistry/stereochemistry-topic/chirality-r-s-system/v/chiral-examples-1?utm_source=YT&utm_medium=Desc&utm_campaign=organicchemistry Organic Chemistry on Khan Academy: Carbon can form covalent bonds with itself and other elements to create a mind-boggling array of structures. In organic chemistry, we will learn about the reactions chemists use to synthesize crazy carbon based structures, as well as the analytical methods to characterize them. We will also think about how those reactions are occurring on a molecular level with reaction mechanisms. Simply put, organic chemistry is like building with molecular Legos. Let's make some beautiful organic molecules! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Organic Chemistry channel: https://www.youtube.com/channel/UCNKPjijOc0WEJ7DIV_Vay3g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 865964 Khan Academy
Introduction to the Black-Scholes formula | Finance & Capital Markets | Khan Academy
 
10:24
Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/black-scholes/v/implied-volatility?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/interest-rate-swaps-tut/v/interest-rate-swap-2?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Interest is the basis of modern capital markets. Depending on whether you are lending or borrowing, it can be viewed as a return on an asset (lending) or the cost of capital (borrowing). This tutorial gives an introduction to this fundamental concept, including what it means to compound. It also gives a rule of thumb that might make it easy to do some rough interest calculations in your head. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 389105 Khan Academy
Mortgage-backed securities I | Finance & Capital Markets | Khan Academy
 
07:57
Part I of the introduction to mortgage-backed securities. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/mort-backed-secs-tut/v/mortgage-backed-securities-ii?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/derivative-securities/mort-backed-secs-tut/v/mortgage-back-security-overview?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: In many commodities markets, it is very helpful for buyers or sellers to lock-in future prices. This is what both forwards and futures allow for. This tutorial explains how they work and what the difference is between the two. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 444258 Khan Academy
Transcription and mRNA processing | Biomolecules | MCAT | Khan Academy
 
10:25
Introduction to transcription including the role of RNA polymerase, promoters, terminators, introns and exons. Watch the next lesson: https://www.khanacademy.org/test-prep/mcat/biomolecules/dna/v/speed-and-precision-of-dna-replication?utm_source=YT&utm_medium=Desc&utm_campaign=mcat Missed the previous lesson? https://www.khanacademy.org/test-prep/mcat/biomolecules/dna/v/leading-and-lagging-strands-in-dna-replication?utm_source=YT&utm_medium=Desc&utm_campaign=mcat MCAT on Khan Academy: Go ahead and practice some passage-based questions! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s MCAT channel: https://www.youtube.com/channel/UCDkK5wqSuwDlJ3_nl3rgdiQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 587250 Khan Academy
Introduction to the unit circle | Trigonometry | Khan Academy
 
09:04
Extending SOH CAH TOA so that we can define trig functions for a broader class of angles Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/trigonometry/unit-circle-trig-func/Trig-unit-circle/e/unit_circle?utm_source=YT&utm_medium=Desc&utm_campaign=Trigonometry Watch the next lesson: https://www.khanacademy.org/math/trigonometry/unit-circle-trig-func/Trig-unit-circle/v/unit-circle-manipulative?utm_source=YT&utm_medium=Desc&utm_campaign=Trigonometry Missed the previous lesson? https://www.khanacademy.org/math/trigonometry/unit-circle-trig-func/radians_tutorial/v/radians-and-degrees?utm_source=YT&utm_medium=Desc&utm_campaign=Trigonometry Trigonometry on Khan Academy: Big, fancy word, right? Don't be fooled. Looking at the prefix, tri-, you could probably assume that trigonometry ("trig" as it's sometimes called) has something to do with triangles. You would be right! Trig is the study of the properties of triangles. Why is it important? It's used in measuring precise distances, particularly in industries like satellite systems and sciences like astronomy. It's not only space, however. Trig is present in architecture and music, too. Now you may wonder...how is knowing the measurement and properties of triangles relevant to music?? THAT is a great question. Maybe you'll learn the answer from us in these tutorials! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Trigonometry channel: https://www.youtube.com/channel/UCYQSs1lFJZKpyqNQQHYFGjw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 1127082 Khan Academy
Hedge fund strategies: Merger arbitrage 1 | Finance & Capital Markets | Khan Academy
 
05:02
Simple case of merger arbitrage when there is an all cash acquisition. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/investment-vehicles-tutorial/investment-consumption/v/risk-and-reward-introduction?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/investment-vehicles-tutorial/hedge-funds/v/hedge-fund-strategies-long-short-2?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Hedge funds have absolutely nothing to do with shrubbery. Their name comes from the fact that early hedge funds (and some current ones) tried to "hedge" their exposure to the market (so they could, in theory, do well in an "up" or "down" market as long as they were good at picking the good companies). Today, hedge funds represent a huge class investment funds. They are far less regulated than, say, mutual funds. In exchange for this, they aren't allowed to market or take investments from "unsophisticated" investors. Some use their flexibility to mitigate risk, other use it to amplify it. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 108057 Khan Academy
Introduction to limits | Limits | Differential Calculus | Khan Academy
 
11:32
Introduction to limits Watch the next lesson: https://www.khanacademy.org/math/differential-calculus/limits_topic/limits_tutorial/v/limit-by-analyzing-numerical-data?utm_source=YT&utm_medium=Desc&utm_campaign=DifferentialCalculus Differential calculus on Khan Academy: Limit introduction, squeeze theorem, and epsilon-delta definition of limits. About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to KhanAcademy’s Differential Calculus channel: https://www.youtube.com/channel/UCNLzjGl1HBdZrHXo4Vae3iA?sub_confirmation=1 Subscribe to KhanAcademy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 3895017 Khan Academy
Introduction to bonds | Stocks and bonds | Finance & Capital Markets | Khan Academy
 
08:42
What it means to buy a bond. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/stock-and-bonds/bonds-tutorial/v/introduction-to-the-yield-curve?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/stock-and-bonds/bonds-tutorial/v/corporate-debt-versus-traditional-mortgages?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Both corporations and governments can borrow money by selling bonds. This tutorial explains how this works and how bond prices relate to interest rates. In general, understanding this not only helps you with your own investing, but gives you a lens on the entire global economy. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 504283 Khan Academy
Review of B cells, CD4+ T cells and CD8+ T cells | NCLEX-RN | Khan Academy
 
11:07
Review of B cells, CD4+ T cells and CD8+ T cells. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/test-prep/nclex-rn/rn-immune-system/rn-the-immune-system/v/clonal-selection?utm_source=YT&utm_medium=Desc&utm_campaign=Nclex-rn Missed the previous lesson? https://www.khanacademy.org/test-prep/nclex-rn/rn-immune-system/rn-the-immune-system/v/cytotoxic-t-cells?utm_source=YT&utm_medium=Desc&utm_campaign=Nclex-rn NCLEX-RN on Khan Academy: A collection of questions from content covered on the NCLEX-RN. These questions are available under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License (available at http://creativecommons.org/licenses/by-nc-sa/3.0/us/). About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s NCLEX-RN channel: https://www.youtube.com/channel/UCDx5cTeADCvKWgF9x_Qjz3g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 927252 Khan Academy
Types of immune responses: Innate and adaptive, humoral vs. cell-mediated | NCLEX-RN | Khan Academy
 
08:07
Innate vs. adaptive immunity. Humoral adaptive immunity vs. cell-mediated adaptive immunity. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/test-prep/nclex-rn/rn-immune-system/rn-the-immune-system/v/b-lymphocytes-b-cells?utm_source=YT&utm_medium=Desc&utm_campaign=Nclex-rn Missed the previous lesson? https://www.khanacademy.org/test-prep/nclex-rn/rn-immune-system/rn-the-immune-system/v/role-of-phagocytes-in-innate-or-nonspecific-immunity?utm_source=YT&utm_medium=Desc&utm_campaign=Nclex-rn NCLEX-RN on Khan Academy: A collection of questions from content covered on the NCLEX-RN. These questions are available under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License (available at http://creativecommons.org/licenses/by-nc-sa/3.0/us/). About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s NCLEX-RN channel: https://www.youtube.com/channel/UCDx5cTeADCvKWgF9x_Qjz3g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 1500567 Khan Academy
How to grow your brain
 
04:11
Short video going over the idea backed by research that your brain really is like a muscle: the more you use it, the stronger it gets. Join the You Can Learn Anything movement at www.khanacademy.org/YouCanLearnAnything
Views: 455630 Khan Academy
LIBOR | Money, banking and central banks  | Finance & Capital Markets | Khan Academy
 
03:37
London InterBank Offer Rate. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/money-and-banking/federal-reserve/v/fed-open-market-operations?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/money-and-banking/banking-and-money/v/frb-commentary-3-big-picture?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: We all use money and most of us use banks. Despite this, the actual working of the banking system is a bit of a mystery to most (especially fractional reserve banking). This older tutorial (bad handwriting and resolution) starts from a basic society looking to do more than barter and incrementally builds to a modern society with fraction reserve banking. Through this process, you will hopefully gain a deep understanding of how money and banking works in our modern world. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 122134 Khan Academy
Central limit theorem | Inferential statistics | Probability and Statistics | Khan Academy
 
09:49
Introduction to the central limit theorem and the sampling distribution of the mean Watch the next lesson: https://www.khanacademy.org/math/probability/statistics-inferential/sampling_distribution/v/sampling-distribution-of-the-sample-mean?utm_source=YT&utm_medium=Desc&utm_campaign=ProbabilityandStatistics Missed the previous lesson? https://www.khanacademy.org/math/probability/statistics-inferential/normal_distribution/v/ck12-org-more-empirical-rule-and-z-score-practice?utm_source=YT&utm_medium=Desc&utm_campaign=ProbabilityandStatistics Probability and statistics on Khan Academy: We dare you to go through a day in which you never consider or use probability. Did you check the weather forecast? Busted! Did you decide to go through the drive through lane vs walk in? Busted again! We are constantly creating hypotheses, making predictions, testing, and analyzing. Our lives are full of probabilities! Statistics is related to probability because much of the data we use when determining probable outcomes comes from our understanding of statistics. In these tutorials, we will cover a range of topics, some which include: independent events, dependent probability, combinatorics, hypothesis testing, descriptive statistics, random variables, probability distributions, regression, and inferential statistics. So buckle up and hop on for a wild ride. We bet you're going to be challenged AND love it! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to KhanAcademy’s Probability and Statistics channel: https://www.youtube.com/channel/UCRXuOXLW3LcQLWvxbZiIZ0w?sub_confirmation=1 Subscribe to KhanAcademy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 1269101 Khan Academy
ALS - Amyotrophic lateral sclerosis | Miscellaneous | Heatlh & Medicine | Khan Academy
 
04:03
Sal explains the disease ALS, amyotrophic lateral sclerosis, and takes the "ice bucket challenge.". Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/health-and-medicine/healthcare-misc/v/low-salt-diet?utm_source=YT&utm_medium=Desc&utm_campaign=healthandmedicine Missed the previous lesson? https://www.khanacademy.org/science/health-and-medicine/healthcare-misc/v/strokes?utm_source=YT&utm_medium=Desc&utm_campaign=healthandmedicine Health & Medicine on Khan Academy: No organ quite symbolizes love like the heart. One reason may be that your heart helps you live, by moving ~5 liters (1.3 gallons) of blood through almost 100,000 kilometers (62,000 miles) of blood vessels every single minute! It has to do this all day, everyday, without ever taking a vacation! Now that is true love. Learn about how the heart works, how blood flows through the heart, where the blood goes after it leaves the heart, and what your heart is doing when it makes the sound “Lub Dub.” About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Health & Medicine channel: https://www.youtube.com/channel/UC1RAowgA3q8Gl7exSWJuDEw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 132231 Khan Academy
Fundamental theorem of calculus (Part 1) | AP Calculus AB | Khan Academy
 
08:03
The fundamental theorem of calculus shows how, in some sense, integration is the opposite of differentiation. Created by Sal Khan. Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/ap-calculus-ab/ab-antiderivatives-ftc/ab-fundamental-theorem-of-calc/e/the-fundamental-theorem-of-calculus?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB Watch the next lesson: https://www.khanacademy.org/math/ap-calculus-ab/ab-antiderivatives-ftc/ab-fundamental-theorem-of-calc/v/connecting-the-first-and-second-fundamental-theorems-of-calculus?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB Missed the previous lesson? https://www.khanacademy.org/math/ap-calculus-ab/ab-antiderivatives-ftc/ab-antiderivatives-intro/v/antiderivatives-and-indefinite-integrals?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB AP Calculus AB on Khan Academy: Bill Scott uses Khan Academy to teach AP Calculus at Phillips Academy in Andover, Massachusetts, and heÕs part of the teaching team that helped develop Khan AcademyÕs AP lessons. Phillips Academy was one of the first schools to teach AP nearly 60 years ago. About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan AcademyÕs AP Calculus AB channel: https://www.youtube.com/channel/UCyoj0ZF4uw8VTFbmlfOVPuw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 928027 Khan Academy
The kidney and nephron | Renal system physiology | NCLEX-RN | Khan Academy
 
18:38
Overview of how the nephrons in the kidney filter blood and reabsorb water and other molecules. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/test-prep/nclex-rn/rn-renal-system/rn-the-renal-system/v/secondary-active-transport-in-the-nephron?utm_source=YT&utm_medium=Desc&utm_campaign=Nclex-rn Missed the previous lesson? https://www.khanacademy.org/test-prep/nclex-rn/rn-renal-system/rn-the-renal-system/v/urination?utm_source=YT&utm_medium=Desc&utm_campaign=Nclex-rn NCLEX-RN on Khan Academy: A collection of questions from content covered on the NCLEX-RN. These questions are available under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License (available at http://creativecommons.org/licenses/by-nc-sa/3.0/us/). About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s NCLEX-RN channel: https://www.youtube.com/channel/UCDx5cTeADCvKWgF9x_Qjz3g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 2168378 Khan Academy
Intro to vectors & scalars | One-dimensional motion | Physics | Khan Academy
 
08:39
Distance, displacement, speed and velocity. Difference between vectors and scalars. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/physics/one-dimensional-motion/displacement-velocity-time/v/calculating-average-velocity-or-speed?utm_source=YT&utm_medium=Desc&utm_campaign=physics Missed the previous lesson? https://www.khanacademy.org/science/physics/one-dimensional-motion/displacement-velocity-time/v/introduction-to-physics?utm_source=YT&utm_medium=Desc&utm_campaign=physics Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry. About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Physics channel: https://www.youtube.com/channel/UC0oGarQW2lE5PxhGoQAKV7Q?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 3777529 Khan Academy
Introduction to Logarithms
 
09:49
An introduction to logarithms About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything.
Views: 1460985 Khan Academy
Krebs / citric acid cycle | Cellular respiration | Biology | Khan Academy
 
17:47
Overview of the Krebs or Citric Acid Cycle Watch the next lesson: https://www.khanacademy.org/science/biology/cellular-respiration-and-fermentation/oxidative-phosphorylation/v/oxidative-phosphorylation-and-the-electon-transport-chain?utm_source=YT&utm_medium=Desc&utm_campaign=biology Missed the previous lesson? https://www.khanacademy.org/science/biology/cellular-respiration-and-fermentation/glycolysis/v/glycolysis-overview?utm_source=YT&utm_medium=Desc&utm_campaign=biology Biology on Khan Academy: Life is beautiful! From atoms to cells, from genes to proteins, from populations to ecosystems, biology is the study of the fascinating and intricate systems that make life possible. Dive in to learn more about the many branches of biology and why they are exciting and important. Covers topics seen in a high school or first-year college biology course. About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's Biology channel: https://www.youtube.com/channel/UC82qE46vcTn7lP4tK_RHhdg?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 3838163 Khan Academy
Leading and lagging strands in DNA replication | MCAT | Khan Academy
 
10:19
Roles of DNA polymerase, primase, ligase, helicase and topoisomerase in DNA replication. An explanation of leading and lagging strands. Watch the next lesson: https://www.khanacademy.org/test-prep/mcat/biomolecules/dna/v/transcription-and-mrna-processing?utm_source=YT&utm_medium=Desc&utm_campaign=mcat Missed the previous lesson? https://www.khanacademy.org/test-prep/mcat/biomolecules/dna/v/telomeres-and-single-copy-dna-vs-repetitive-dna?utm_source=YT&utm_medium=Desc&utm_campaign=mcat MCAT on Khan Academy: Go ahead and practice some passage-based questions! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s MCAT channel: https://www.youtube.com/channel/UCDkK5wqSuwDlJ3_nl3rgdiQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 436249 Khan Academy
Proof by induction | Sequences, series and induction | Precalculus | Khan Academy
 
09:23
Proving an expression for the sum of all positive integers up to and including n by induction Watch the next lesson: https://www.khanacademy.org/math/precalculus/seq_induction/proof_by_induction/v/alternate-proof-to-induction-for-integer-sum?utm_source=YT&utm_medium=Desc&utm_campaign=Precalculus Missed the previous lesson? https://www.khanacademy.org/math/precalculus/prob_comb/prob_combinatorics_precalc/v/birthday-probability-problem?utm_source=YT&utm_medium=Desc&utm_campaign=Precalculus Precalculus on Khan Academy: You may think that precalculus is simply the course you take before calculus. You would be right, of course, but that definition doesn't mean anything unless you have some knowledge of what calculus is. Let's keep it simple, shall we? Calculus is a conceptual framework which provides systematic techniques for solving problems. These problems are appropriately applicable to analytic geometry and algebra. Therefore....precalculus gives you the background for the mathematical concepts, problems, issues and techniques that appear in calculus, including trigonometry, functions, complex numbers, vectors, matrices, and others. There you have it ladies and gentlemen....an introduction to precalculus! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Precalculus channel: https://www.youtube.com/channel/UCBeHztHRWuVvnlwm20u2hNA?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 801862 Khan Academy
Production possibilities frontier | Microeconomics | Khan Academy
 
10:59
Tradeoffs for a hunter gatherer and the production possibilities frontier, and the notion of "ceteris paribus" (which means "everything else held equal"). Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/microeconomics/choices-opp-cost-tutorial/production-possibilities/v/opportunity-cost?utm_source=YT&utm_medium=Desc&utm_campaign=microeconomics Missed the previous lesson? https://www.khanacademy.org/economics-finance-domain/microeconomics/consumer-producer-surplus/externalities-topic/v/tragedy-of-the-commons?utm_source=YT&utm_medium=Desc&utm_campaign=microeconomics Microeconomics on Khan Academy: Topics covered in a traditional college level introductory microeconomics course About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's Microeconomics channel: https://www.youtube.com/channel/UC_6zQ54DjQJdLodwsxAsdZg Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 1188213 Khan Academy
Hedge funds, venture capital, and private equity | Finance & Capital Markets | Khan Academy
 
02:54
Similarities in compensation structure for hedge funds, venture capital firms, and private equity investors. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/investment-vehicles-tutorial/hedge-funds/v/hedge-fund-strategies-long-short-1?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/investment-vehicles-tutorial/hedge-funds/v/are-hedge-funds-bad?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Hedge funds have absolutely nothing to do with shrubbery. Their name comes from the fact that early hedge funds (and some current ones) tried to "hedge" their exposure to the market (so they could, in theory, do well in an "up" or "down" market as long as they were good at picking the good companies). Today, hedge funds represent a huge class investment funds. They are far less regulated than, say, mutual funds. In exchange for this, they aren't allowed to market or take investments from "unsophisticated" investors. Some use their flexibility to mitigate risk, other use it to amplify it. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 140505 Khan Academy
Negative externalities | Consumer and producer surplus | Microeconomics | Khan Academy
 
06:00
Taking negative externalities into account when thinking about the optimal equilibrium price and quantity Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/microeconomics/consumer-producer-surplus/externalities-topic/v/taxes-for-factoring-in-negative-externalities?utm_source=YT&utm_medium=Desc&utm_campaign=microeconomics Missed the previous lesson? https://www.khanacademy.org/economics-finance-domain/microeconomics/consumer-producer-surplus/deadweight-loss-tutorial/v/taxes-and-perfectly-elastic-demand?utm_source=YT&utm_medium=Desc&utm_campaign=microeconomics Microeconomics on Khan Academy: Topics covered in a traditional college level introductory microeconomics course About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's Microeconomics channel: https://www.youtube.com/channel/UC_6zQ54DjQJdLodwsxAsdZg Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 304844 Khan Academy
Laplacian intuition
 
05:31
A visual understanding for how the Laplace operator is an extension of the second derivative to multivariable functions.
Views: 109324 Khan Academy
Operons and gene regulation in bacteria
 
10:10
Looking at how regulatory DNA sequences can repress or promote gene transcription (particularly in bacteria operons).
Views: 163131 Khan Academy
DNA cloning and recombinant DNA | Biomolecules | MCAT | Khan Academy
 
11:08
Introduction to DNA cloning. Watch the next lesson: https://www.khanacademy.org/test-prep/mcat/biomolecules/dna-technology/v/hybridization-microarray?utm_source=YT&utm_medium=Desc&utm_campaign=mcat Missed the previous lesson? https://www.khanacademy.org/test-prep/mcat/biomolecules/dna-technology/v/dna-libraries-generating-cdna?utm_source=YT&utm_medium=Desc&utm_campaign=mcat MCAT on Khan Academy: Go ahead and practice some passage-based questions! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s MCAT channel: https://www.youtube.com/channel/UCDkK5wqSuwDlJ3_nl3rgdiQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 369205 Khan Academy
Inflammatory response | Human anatomy and physiology | Health & Medicine | Khan Academy
 
14:35
Overview of the inflammatory response. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/introduction-to-immunology/v/rn-blood-cell-lineages?utm_source=YT&utm_medium=Desc&utm_campaign=healthandmedicine Missed the previous lesson? https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/introduction-to-immunology/v/how-white-blood-cells-move-around?utm_source=YT&utm_medium=Desc&utm_campaign=healthandmedicine Health & Medicine on Khan Academy: No organ quite symbolizes love like the heart. One reason may be that your heart helps you live, by moving ~5 liters (1.3 gallons) of blood through almost 100,000 kilometers (62,000 miles) of blood vessels every single minute! It has to do this all day, everyday, without ever taking a vacation! Now that is true love. Learn about how the heart works, how blood flows through the heart, where the blood goes after it leaves the heart, and what your heart is doing when it makes the sound “Lub Dub.” About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Health & Medicine channel: https://www.youtube.com/channel/UC1RAowgA3q8Gl7exSWJuDEw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 1237075 Khan Academy
Hedge fund structure and fees | Finance & Capital Markets | Khan Academy
 
06:52
Understanding how hedge funds are structured and how the managers get paid. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/investment-vehicles-tutorial/hedge-funds/v/are-hedge-funds-bad?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/investment-vehicles-tutorial/hedge-funds/v/hedge-funds-intro?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Hedge funds have absolutely nothing to do with shrubbery. Their name comes from the fact that early hedge funds (and some current ones) tried to "hedge" their exposure to the market (so they could, in theory, do well in an "up" or "down" market as long as they were good at picking the good companies). Today, hedge funds represent a huge class investment funds. They are far less regulated than, say, mutual funds. In exchange for this, they aren't allowed to market or take investments from "unsophisticated" investors. Some use their flexibility to mitigate risk, other use it to amplify it. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 214551 Khan Academy
Shorting stock | Stocks and bonds | Finance & Capital Markets | Khan Academy
 
09:32
What does it mean to short a stock? Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/core-finance/stock-and-bonds/shorting-stock/v/shorting-stock-2?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Missed the previous lesson? Watch here: https://www.khanacademy.org/economics-finance-domain/core-finance/stock-and-bonds/shorting-stock/v/basic-shorting?utm_source=YT&utm_medium=Desc&utm_campaign=financeandcapitalmarkets Finance and capital markets on Khan Academy: Can you sell something that you borrowed from someone else? Why, yes, you can and it is called "shorting". Why would you do this? Well, you can now make money if the price goes down. Is this bad? This tutorial has your answers. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Finance and Capital Markets channel: https://www.youtube.com/channel/UCQ1Rt02HirUvBK2D2-ZO_2g?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 460572 Khan Academy
Multivariable functions | Multivariable calculus | Khan Academy
 
06:02
An introduction to multivariable functions, and a welcome to the multivariable calculus content as a whole. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to KhanAcademy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 444953 Khan Academy
Introduction to motion (part 3)
 
04:32
Using the basic equations of distance and velocity to solve motion problems
Views: 106601 Khan Academy
Economic profit vs accounting profit | Microeconomics | Khan Academy
 
08:06
Difference between a firm's accounting and economic profit Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/microeconomics/firm-economic-profit/economic-profit-tutorial/v/depreciation-and-opportunity-cost-of-capital?utm_source=YT&utm_medium=Desc&utm_campaign=microeconomics Missed the previous lesson? https://www.khanacademy.org/economics-finance-domain/microeconomics/choices-opp-cost-tutorial/marginal-utility-tutorial/v/types-of-indifference-curves?utm_source=YT&utm_medium=Desc&utm_campaign=microeconomics Microeconomics on Khan Academy: Topics covered in a traditional college level introductory microeconomics course About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's Microeconomics channel: https://www.youtube.com/channel/UC_6zQ54DjQJdLodwsxAsdZg Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 334206 Khan Academy
Formal definition for limit of a sequence | Series | AP Calculus BC | Khan Academy
 
04:49
A sequence is "converging" if its terms approach a specific value at infinity. This video is a more formal definition of what it means for a sequence to converge. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/math/ap-calculus-bc/bc-series/bc-series-opt-vids/v/proving-a-sequence-converges?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusBC Missed the previous lesson? https://www.khanacademy.org/math/ap-calculus-bc/bc-series/bc-power-series/v/finding-function-from-series-by-integrating?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusBC AP Calculus BC on Khan Academy: Learn AP Calculus BC - everything from AP Calculus AB plus a few extra goodies, such as Taylor series, to prepare you for the AP Test About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's AP Calculus BC channel: https://www.youtube.com/channel/UC5A2DBjjUVNz8axD-90jdfQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 307926 Khan Academy
Strokes | Miscellaneous | Heatlh & Medicine | Khan Academy
 
06:08
Basics of strokes. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/health-and-medicine/healthcare-misc/v/als-ice-bucket-challenge?utm_source=YT&utm_medium=Desc&utm_campaign=healthandmedicine Missed the previous lesson? https://www.khanacademy.org/science/health-and-medicine/healthcare-misc/v/thrombo-emboli-and-thromboembolisms?utm_source=YT&utm_medium=Desc&utm_campaign=healthandmedicine Health & Medicine on Khan Academy: No organ quite symbolizes love like the heart. One reason may be that your heart helps you live, by moving ~5 liters (1.3 gallons) of blood through almost 100,000 kilometers (62,000 miles) of blood vessels every single minute! It has to do this all day, everyday, without ever taking a vacation! Now that is true love. Learn about how the heart works, how blood flows through the heart, where the blood goes after it leaves the heart, and what your heart is doing when it makes the sound “Lub Dub.” About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Health & Medicine channel: https://www.youtube.com/channel/UC1RAowgA3q8Gl7exSWJuDEw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 203341 Khan Academy
Comparative advantage specialization and gains from trade | Microeconomics | Khan Academy
 
08:56
How two parties can get better outcomes by specializing in their comparative advantage and trading Watch the next lesson: https://www.khanacademy.org/economics-finance-domain/microeconomics/choices-opp-cost-tutorial/gains-from-trade-tutorial/v/comparative-advantage-and-absolute-advantage?utm_source=YT&utm_medium=Desc&utm_campaign=microeconomics Missed the previous lesson? https://www.khanacademy.org/economics-finance-domain/microeconomics/choices-opp-cost-tutorial/production-possibilities/v/economic-growth-through-investment?utm_source=YT&utm_medium=Desc&utm_campaign=microeconomics Microeconomics on Khan Academy: Topics covered in a traditional college level introductory microeconomics course About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's Microeconomics channel: https://www.youtube.com/channel/UC_6zQ54DjQJdLodwsxAsdZg Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 588589 Khan Academy

Viagra pfizer 25 mg precio
Abel book com guest levitra online site
Palexia 50 mg posologia aciclovir
Posologia cephalexin 500mg
Provera pills 5mg