Question

Cos(2π-x)-sin(3π/2+x)=1

Answer 1

Упростить :  cos(2π-x) = cosx, sin(3π/2 +x) = -cosx.
Получим уравнение cos x + cos x = 1,
2 cos x = 1,
cos x = 1/2,   arccos(1/2)= π/3,
x = +- π/3 +2πn, n∈Z.