第2002题:运用两次分部积分法
计算 ∫e5x+7dx\int \mathrm{e}^{\sqrt{5x+7}} dx∫e√5x+7dx .
A. 25(5x+7−1)e5x+7\dfrac{2}{5} (\sqrt{5x+7}-1) \mathrm{e}^{\sqrt{5x+7}}52(√5x+7−1)e√5x+7+C +C+C
B. 52(5x+7−1)e5x+7\dfrac{5}{2} (\sqrt{5x+7}-1) \mathrm{e}^{\sqrt{5x+7}}25(√5x+7−1)e√5x+7 +C+C+C
C. 57(5x+7−1)e5x+7\dfrac{5}{7} (\sqrt{5x+7}-1) \mathrm{e}^{\sqrt{5x+7}} 75(√5x+7−1)e√5x+7 +C+C+C
D. 75(5x+7−1)e5x+7\dfrac{7}{5} (\sqrt{5x+7}-1) \mathrm{e}^{\sqrt{5x+7}} 57(√5x+7−1)e√5x+7 +C+C+C
提示:
∫xexdx\int x \mathrm{e}^{x} dx ∫xexdx =ex(x−1)+C=\mathrm{e}^x (x-1) +C=ex(x−1)+C