tanx.sinx/tanx-sinx=tanx+sinx/tanxsinx
问题描述：
tanx.sinx/tanx-sinx=tanx+sinx/tanxsinx
证相等
答
1-cos ^2x=sin^2x 方程两边同时乘以sinx^2/cosx^2sin^2x/cos^2x - sin^2x =sin^2x sin^2x/cos^2xtan^2x -sin^2x =sin^2 x tan^2 x(tanx-sinx)(tanx+sinx)=(sinx tanx) (sinx tanx)divide both sides by sinxtanx/(ta...