Sinx-sin^2x=cos^2x-cosx
Sinx+cosx=cos²x+sin²x sinx+sin(π/2-x)=1 2sinπ/4*cos(x-π/4)=1 2*√2/2*cos(x-π/4)=1 cos(x-π/4)=1/√2 x-π/4=-π/4+2πn U x-π/4=π/4+2πk x=2πn,n∈z U x=π/2+2πk,k∈z