Question

2sin^2x + 2sinxcosx = 0

Answer 1

(sinx)^2+sin2x=0

We know that sin2x= 2sinx*cosx

==> (sinx)^2+2sinx*cosx=0

==> sinx(sinx+2cosx)=0

Then sinx=0 or sinx+2cosx=0

sinx+2xosx=0

==> sinx=-2cosx

==> sinx/cosx= -2

==> tanx=-2

==> x= (n+1)tan 2