-2sin(п/2+2x)+3=2cos^2x-1

Question

-2sin(п/2+2x)+3=2cos^2x-1

Answer 1

-2cos2x=2cos^2x-cos^2x-sin^2x
-2cos2x=cos^2x-sin^2x
-2(cos^2x-sin^2x)=cos^2x-sin^2x
3(cos^2x-sin^2x)=0
cos^2x-sin^2x=0
cos2x=0
2x=pi/2+pik,k∈z
x=pi/4+pi/2*k,k∈z