Question

решите уравнение sin2x - 2cosx = 0

Answer 1

sin2x-2cosx=0

2 sin x cos x - 2 cos x = 0

2 cos x (sin x - 1) = 0

cos x = 0                   sin x = 1

x=π/2+πn,n∈Z           x=π/2+2πn, n∈Z

Ответ. х=π/2+πn, n∈Z