2sinθcosθ−cosθ1−sinθ+sin2θ−cos2θ=cotθ
LHS2sinθcosθ−cosθ1−sinθ+sin2θ−cos2θ=cosθ(2sinθ−1)1−cos2θ+sin2θ−sinθ
=cosθ(2sinθ−1)sin2θ+sin2θ−sinθ[∵1−cos2θ=sin2θ]
=cosθ(2sinθ−1)2sin2θ−sinθ=cosθ(2sinθ−1)sin(2sinθ−1)=cosθsinθ=cotθ=RHS
Hence proved.
If cos θ=513, find the value of sin2θ−cos2θ2 sin θ cos θ×1tan2θ