>>32
それなら0じゃないかな？

tan^2θ+(1-tan^4θ)(1-sin^2θ)
=tan^2θ+{1-(1/cos^2θ-1)^2*}cos^2θ
=tan^2θ+ cos^2θ - 1/cos^2θ +1 - cos^2θ
=tan^2θ - 1/cos^2θ + cos^2θ +1 - cos^2θ
= - 1 + cos^2θ + sin^2θ
=0