Cos(2arcsin(-3/4)) найдите решение,помогите

Question

Cos(2arcsin(-3/4)) найдите решение,помогите

Answer 1

Cos(2arcsin(-3/4)) = cos(-2arcsin(3/4)) = cos(2arcsin(3/4)) = 1 - 2 * (sin (arcsin(3/4)))^2 = 1 - 2 * (3/4)^2 = 1 - 18/16 = 1 - 9/8 = -1/8