tan^2=?

题目

tan^2=?

答案

tan^2θ表示θ的正切值(tanθ)的平方
tan^2θ=(tanθ)^2=(sinθ/cosθ)^2 = sin^2θ/cos^2θ
= sin^2θ/（1-sin^2θ)
= (1-cos^2θ)/cos^2θ