设sin^2 x-sinx cosx-6 cos^2 x=0,求(cos2x-sin2x)/(1-cos2x)(1-tan2x)的值
问题描述:
设sin^2 x-sinx cosx-6 cos^2 x=0,求(cos2x-sin2x)/(1-cos2x)(1-tan2x)的值
完整点的
答
sin^2 x-sinx cosx-6 cos^2 x=0
(sinx-3cosx)(sinx+2cosx)=0
sinx=3cosx
或sinx=-2cosx