Sinx+sin(x+3П/2)=1-0.5sin2x

Question

Sinx+sin(x+3П/2)=1-0.5sin2x

Answer 1

Sinx+sinxcos(3pi/2)+sin (3pi/2) cosx=1-sinxcosx
sinx-cosx=1-sinxcosx
sinx+sinxcosx=1+cosx
sinx (1+cosx)=1+cosx
sinx=1
x=pi/2+2pin