Use the figure to find the exact value of the following trigonometric function.

Question

Answer 1

Draw the geometry diagram.

From the geometry diagram

sin(œ) =3/5

cos(œ) = 4/5

cos(2œ) = cos^2(œ) - sin^2(œ)

             =(4/5)^2 - (3/5)^2

            =(16/25)-(9/25)

            =(16-9)/25

            = 7/25