求大神 啊 过程要有啊!! 财富值要没了就这么多了
设 x - 1 = y,则[x/(x-1)]^(x+2) = [(y+1)/y]^(y+3) = (1 + 1/y)^y * (1+1/y)^3
所以,这个极限 = e * (1 + 0)^3 = e
(sinx)^3 dx = (sinx)^2 *(sinxdx)
= [1- (cosx)^2] (-1)d(cosx)
= [(cosx)^2 - 1] d(cosx)
所以,不定积分= 1/3(cosx)^3 - cosx + C