Question #7218e

1 Answer
Apr 16, 2016

See below

Explanation:

LHS=left hand side, RHS =right hand side

LHS=sin(2x+x)1+2cos2x

=sin2xcosx+cos2xsinx1+2cos2x

=(2sinxcosx)cosx+(12sin2x)sinx1+2cos2x

=2sinxcos2x+sinx2sin3x1+2(12sin2x)

=2sinx(1sin2x)+sinx2sin3x1+24sin2x

=2sinx2sin3x+sinx2sin3x34sin2x

=3sinx4sin3x34sin2x

=sinx(34sin2x)34sin2x

=sinx

=RHS