x=sint则,dx=cotdt
原式=∫(sin²tcost)/(cos²t)²dt=∫x²/(1-x²)² dx
=∫ 【1/(4 (-1 + x)^2) + 1/(4 (-1 + x)) + 1/(4 (1 + x)^2) - 1/(4 (1 + x))】dx
=..
大一高数求积分,求(sint)的平方／(cost)的三方 •dt的积分
x=sint则,dx=cotdt
原式=∫(sin²tcost)/(cos²t)²dt=∫x²/(1-x²)² dx
=∫ 【1/(4 (-1 + x)^2) + 1/(4 (-1 + x)) + 1/(4 (1 + x)^2) - 1/(4 (1 + x))】dx
=..