证明tan^2x-sin^2x=tan^2 sin^2x

分类: 作业答案 • 2023-01-07 14:12:36

问题描述：

答

tan^2x-sin^2x=sin^2x/cos^2x-sin^2x=
(1/cos^2x-1)sin^2x=[(1-cos^2x)/cos^2x]sin^2x=
[sin^2x/cos^2x]sin^2x=tan^2xsin^2x