Need help proving the cos(a+b) = (cos a)(cos b)(sin a)(sin b) trigonometric identity? This free video lesson will show you how. From Ramanujan to calculus cocreator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to verify this fundamental trigonometric identity.
 Hot
 Latest

How To: Remember "greater than" & "less than" symbols

How To: Find the slope of a line given 2 points with fractions

How To: Prove a triangle inscribed in a circle is right angled

How To: Factor perfect square trinomials in algebra

How To: Find the equation of a circle given: center & tangent

How To: Convert Fahrenheit to Celsius with a formula

How To: Find the formula of a piecewise function given a graph

How To: Divide decimals

How To: Graph x squared & the square root of x

How To: Find the common ratio of a geometric series

How To: Find a number given Its percent

How To: Find the Percent Given Two Numbers

How To: Convert between diameter and radius

How To: Figure out the domain & range of a piecewise function

How To: Identify characteristics of a sample during a survey

How To: Learn Calculus in 20 minutes

How To: Find the 100th term in a sequence

How To: Find the equation of a line given 1 point

How To: Do long division with decimals

How To: Remember "greater than" & "less than" symbols

How To: Find the slope of a line given 2 points with fractions

How To: Prove a triangle inscribed in a circle is right angled

How To: Factor perfect square trinomials in algebra

How To: Find the equation of a circle given: center & tangent

How To: Convert Fahrenheit to Celsius with a formula

How To: Find the formula of a piecewise function given a graph

How To: Divide decimals

How To: Graph x squared & the square root of x

How To: Find the common ratio of a geometric series

How To: Find a number given Its percent

How To: Find the Percent Given Two Numbers

How To: Convert between diameter and radius

How To: Figure out the domain & range of a piecewise function

How To: Identify characteristics of a sample during a survey

How To: Learn Calculus in 20 minutes

How To: Find the 100th term in a sequence

How To: Find the equation of a line given 1 point

How To: Do long division with decimals
Be the First to Comment
Share Your Thoughts