Решить уравнения: cos(5/2п + х) = -1 sin(9/2п + х) = -1

1)cos(5π/2+x)=-1
cos(2π+π/2+x)=-1
cos(π/2+x)=-1
sinx=-1
x=-π/2+2πn
2)sin(9π/2+x)=-1
sin(4π+π/2+x)=-1
sin(π/2+x)=-1
cosx=-1
x=π+2ππn