用直接积分法求不定积分,∫cot²xdx怎么算?

用直接积分法求不定积分,∫cot²xdx怎么算?
用直接积分法求不定积分,∫cot²xdx怎么算?

用直接积分法求不定积分,∫cot²xdx怎么算?
∫cot²xdx
=S(csc^2x-1)dx
=Scsc^2xdx-Sdx
=-cotx-x+c

cot²x=csc²x-1
(cotx)'=csc²x