In this math video, Julie Harland teaches the derivation of double angle trigonometry formula. She demonstrates examples using the formulas for cosine, sine, and tangent. There are three different ways to compute the cosine of 2A, two ways to compute the sine of 2A, and one way to compute the tangent of 2A. Julie also provides tips on how to choose which formula to use based on the information provided. Additionally, she shows how the tangent of 2A can be calculated using the equations for cosine and sine.
Video derives the double angle trigonometry formula and provides examples using the formula.
More free YouTube videos by Julie Harland are organized at http://yourmathgal.com