Cos(-x)-sin(3pi/2-x)=1

Question

Cos(-x)-sin(3pi/2-x)=1

Answer 1

Cos(-x)-sin(3Pi/2-x)=1
cos(x)+cos(x)=1
2cos(x)=1
cos(x)=1/2
x=+/-Pi/3+2Pin; n∈Z