Решите уравнение cos2x+sin²x=1
Cos2x+sin²x=1 cos²x-sin²x+sin²x=1 cos²x-1=0 (cosx-1)(cosx+1)=0 cosx-1=0 cosx+1=0 cosx=1 cosx=-1 x₁=2πn, n∈Z x₂=π+2πn, n∈Z