Question #18291

1 Answer
Jan 18, 2017

LHS=(1-cos2x +sin2x)/(1+cos2x +sin2x)

using formula 1-cos2x=2sin^2x and 1+cos2x=2cos^2x

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

=(2sinx(sinx +cosx))/(2cosx(cosx +sinx)

=(cancel2sinxcancel((sinx +cosx)))/(cancel2cosxcancel((cosx +sinx))

=sinx/cosx

=tanx=RHS

Proved