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求x/(x²-2x+2)²不定积分

题目详情
求x/(x²-2x+2)²不定积分
▼优质解答
答案和解析
I = ∫xdx/(x^2-2x+2)^2 = ∫xdx/[(x-1)^2+1]^2,
令 x-1= tant, 则 x=1+tant, dx=(sect)^2dt,
I = ∫xdx/[(x-1)^2+1]^2 = ∫(1+tant)dt/(sect)^2
= ∫[(cost)^2+sintcost]dt
= ∫[1/2+(1/2)cos2t+sintcost]dt
= t/2+(1/4)sin2t+(1/2)(sint)^2+C
= (1/2)arctan(x-1)+(1/2)x(x-1)/(x^2-2x+2)+C