Question

2сos^2(3pi/2 + x) + sin2x=0

Answer 1

2sin²x+2sinxcosx=0
2sinx(sinx+cosx)=0
sinx=0⇒x=πn,n∈z
sinx+cosx=0/cosx
tgx+1=0
tgx=1⇒x=π/4+πk,k∈z