[sin(A-派)cot(A-2派)]/[cos(A-派)tan(A-2派)]
问题描述：
[sin(A-派)cot(A-2派)]/[cos(A-派)tan(A-2派)]
答
sin(A-派)=-sin Acos(A-派)=-cos Acot A=cos A/sin Atan A=sin A/cos A所以[sin(A-派)cot(A-2派)]/[cos(A-派)tan(A-2派)]=-sin Acot A/(-cos Atan A)=-cos A/(-sin A)=cot A