The indefinite integral of re'. for any real constant \(C\) is ____________
A. C B. \(x+ e ^{x}+c\) C. \(x^{2}+ e ^{-1}+c\) D. ei \((x-1)+c\)
Correct Answer: D
Explanation
\(\int \cdot \operatorname{se}^{x} d x\) This is integration by part. We recall the relationship \(\int u d-u x-\int v d u\) Let \(u=x \cdot \frac{d u}{d x}=1 \Rightarrow d u=d x\) \begin{aligned} &d v=e^{x} d x \\ &r=\int e^{x} d x=e x \\ &\int u d y^{\prime}=x \cdot e^{\prime}-\int e^{x} d x \\ &=x e^{x}-e^{x}+c \end{aligned} We factorize \(e\) \begin{aligned} &e^{x}(x-1)+c \\ &x=\int e^{x} d x=e^{x} \\ &\int w h=x \cdot e^{x}-\int e^{x} d x \end{aligned} \(= xe ^{ y }- e ^{ x }+ c\) We factorize \(e ^{ x }\) \(e ^{ x }(x-1)+ c\)