Use identities to find values of the sine and cosine functio

Use identities to find values of the sine and cosine functions of the function for the angle measure. 2 theta, given sin theta = -squareroot 6/7 and cos theta > 0 cos 2 theta = (Simplify your answer, including any radicals. Use integers or fractions for any numbers in the expression.)

Solution

sin theta =-sqrt6/7

cos 2 theta=1-2sin²theta =1-2(6/49)=37/49

cos 2 theta=37/49

And that\'s the answer.