∫ [cos^3(x)]/[sin^2 (x)]dx
问题描述：
∫ [cos^3(x)]/[sin^2 (x)]dx
答
∫ [cos^3(x)]/[sin^2 (x)]dx
=积分:(cos^2x)/(sin^2x)dsinx
=积分:(1-sin^2x)/sin^2x)dsinx
=积分;1/sin^2xdsin^2x-积分1dsinx
=-1/sinx-sinx+C