化简-cos(a)cot(a)+csc(a)-sin(a)

问题描述:

化简-cos(a)cot(a)+csc(a)-sin(a)

-cos(a)cot(a)+csc(a)-sin(a)
=-cosa*cosa/sina+1/sina-sina
=(-cos²a+1)/sina-sina
=(sin²a)/sina-sina
=sina-sina
=0