In this lesson, Julie Harland teaches us how to use trig identities to make computations. She walks us through a problem where we're given the cosine of 2A and we're trying to find the cosine, sine, and tangent of A. Julie shows us how to use the formula for the cosine of 2A to find the cosine of A and then walks us through different methods for finding the sine of A. She reminds us to be careful of signs and offers a variety of ways to approach similar problems.
Using Trig Identities to make computations.
More free YouTube videos by Julie Harland are organized at http://yourmathgal.com