Question

If sin 2X = COS ZY and m2X = 72°, what is the measure of ZY?

18°
072°
90°
108°

Answer 1

The answer would be 18’

Answer 2

18°

Explanation:

sin 2x=cos zy

m(2x)=72°

cos(π/2-a)=sin a

cos(π/2-72°)=sin72°

cos18°=sin72°

=>m(zy)=18°