证明:1+cos^2a/sin^2a=1/sin^2a
问题描述:
证明:1+cos^2a/sin^2a=1/sin^2a
RT
答
1+cos^2a/sin^2a=sin^2a/sin^2a+cos^2a/sin^2a
=(sin^2a+cos^2a)/sin^2a
=1/sin^2a.