求d/dx∫上限-1下限-exIn(1+x²)dx=
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首先,我们可以使用换元法来计算此积分。设 u = 1 + x^2,则 x = sqrt(u - 1), dx = (1/2) * (u - 1)^(-1/2) du。将这个换元代入到原式中得到:d/dx ∫上限-1下限 -ex * In(1+x²) dx= d/du (∫上限-1下限 -e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2) du)我们可以将导数和积分的次序交换,也就是:= (∫上限-1下限 d/du (-e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2)) du)接下来,我们来计算这个积分中的导数部分:d/du (-e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))= (-e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))’应用乘积法则和链式法则得到:= -e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))’ + (-e(sqrt(u-1
咨询记录 · 回答于2023-07-15
求d/dx∫上限-1下限-exIn(1+x²)dx=
首先,我们可以使用换元法来计算此积分。设 u = 1 + x^2,则 x = sqrt(u - 1), dx = (1/2) * (u - 1)^(-1/2) du。将这个换元代入到原式中得到:d/dx ∫上限-1下限 -ex * In(1+x²) dx= d/du (∫上限-1下限 -e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2) du)我们可以将导数和积分的次序交换,也就是:= (∫上限-1下限 d/du (-e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2)) du)接下来,我们来计算这个积分中的导数部分:d/du (-e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))= (-e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))’应用乘积法则和链式法则得到:= -e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))’ + (-e(sqrt(u-1
应用乘积法则和链式法则得到:= -e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))’ + (-e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2)) * (u - 1)‘^(-1/2)= -e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))’ + (-e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2)) * (-1/2) * (u - 1)^(-3/2) * (u - 1)’= -e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1/2))’ - e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1) * (u - 1)’= -e(sqrt(u-1)) * In(u) * (1/2) * ((u - 1)^(-1/2))’ - e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1) * (u - 1)’= -e
= -e(sqrt(u-1)) * In(u) * (1/2) * (-1/2) * (u - 1)^(-3/2) - e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1) * 1= e(sqrt(u-1)) * In(u) * (1/4) * (u - 1)^(-3/2) - e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1)
现在我们将这个导数代入到积分中得到:(∫上限-1下限 e(sqrt(u-1)) * In(u) * (1/4) * (u - 1)^(-3/2) - e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1) du)对这个积分进行计算,我们可以将此积分分成两个部分,然后分别计算:第一部分: (∫上限-1下限 e(sqrt(u-1)) * In(u) * (1/4) * (u - 1)^(-3/2) du)第二部分: (∫上限-1下限 - e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1) du)
对于第一部分,我们可以使用分部积分法来计算,设 f (u) = e(sqrt(u-1)) 和 g’(u) = In(u) * (1/4) * (u - 1)^(-3/2),则有:f’(u) = (1/2) * e(sqrt(u-1)) * (u - 1)^(-1/2) 和 g(u) = -In(u) * (1/4) * (u - 1)^(-1/2)根据分部积分法的公式 ∫ u * v’ du = u * v - ∫ u’ * v du,我们可以得到:
∫上限-1下限 e(sqrt(u-1)) * In(u) * (1/4) * (u - 1)^(-3/2) du= (e(sqrt(u-1)) * (-In(u) * (1/4) * (u - 1)^(-1/2))) 上限-1下限 - ∫上限-1下限 (-In(u) * (1/4) * (u - 1)^(-1/2)) * (1/2) * e(sqrt(u-1)) * (u - 1)^(-1/2) du= e(sqrt(u-1)) * (-In(u) * (1/4) * (u - 1)^(-1/2)) 上限-1下限 + (1/8) * (∫上限-1下限 In(u) * (u - 1)^(-1) du)
对于第二部分,我们可以直接计算这个积分,得到:(∫上限-1下限 - e(sqrt(u-1)) * In(u) * (1/2) * (u - 1)^(-1) du)= (-In(u) * (1/2) * (u - 1)^(-1)) 上限-1下限 + (1/2) * (∫上限-1下限 In(u) * (u - 1)^(-1) du)综上所述,我们可以将原式分成两部分进行计算:第一部分: (e(sqrt(u-1)) * (-In(u) * (1/4) * (u - 1)^(-1/2))) 上限-1下限 + (1/8) * (∫上限-1下限 In(u) * (u - 1)^(-1) du)
第二部分: (-In(u) * (1/2) * (u - 1)^(-1)) 上限-1下限 + (1/2) * (∫上限-1下限 In(u) * (u - 1)^(-1) du)