How to simplify sin^2x/(cos^2+3cosx+2)=(1-cosx)/(2+cosx)?

(Sin^2X)/(cos^2x+3cosX+2)=(1-cosX)/(2+cosx)

1 Answer
Feb 1, 2018

LHS=sin^2x/(cos^2x+3cosx+2)

=sin^2x/(cos^2x+cosx+2cosx+2)

=(1-cos^2x)/((cosx(cosx+1)+2(cosx+1))

=((1-cosx)(1+cosx))/((cosx+1)(cosx+2))

=(1-cosx)/(2+cosx)=RHS