证明:tan^2角-sin^2角=tan^2角sin^2角
问题描述:
证明:tan^2角-sin^2角=tan^2角sin^2角
答
tan^2角-sin^2角
= sin^2角/cos^2角- sin^2角
= sin^2角 * (1-cos^2角) / cos^2角
=sin^2角* sin^2角/ cos^2角
=tan^2角sin^2角