You can put this solution on YOUR website! prove that the equation is an identity.
sin^2θ(csc^2θ-1) = cos^2θ
..
Substitute x for theta
start with left-hand side
sin^2x(csc^2x-1)
=sin^2x(1/sin^2x-1)
=1-sin^2x=cos^2x
verified:
left-hand side=right-hand side