(int )_(0)^1x(e)^xdx= __

7.计算下列定积分:-|||-(1) (int )_(0)^1x(e)^-xdx ;-|||-(2)(int )_(1)^xxln xdx;-|||-(3) (

(int )_(0)^+infty x(2)^-xdx=( )(int )_(0)^+infty x(2)^-xdx=( )(int )_(0)^+inft

188 int_(0)^+inftysqrt(x)e^-xdx=A. $\sqrt{\pi}.$B. $\pi.$C. $\frac{\sqrt{\pi}}{2

24.[填空题]int_(-1)^1x^2sin xdx=____24.[填空题]$\int_{-1}^{1}x^{2}\sin xdx=$____

不定积分int (({e)^x+2)}^3(e)^xdx=()A、 int (({e)^x+2)}^3(e)^xdx=()B 、int (({e)^x+2)}^

(int )_(0)^+infty (x)^3(e)^-2xdx= __

定积分(int )_(-1)^1((x)^2020+1)sin xdx=0.（ ）(int )_(-1)^1((x)^2020+1)sin xdx=0错(in

1.求函数 varphi (x)=(int )_(0)^xx(e)^-xdx 的极值.

(2) int x(e)^-xdx;

4.证明：int_(0)^1x^m(1-x)^ndx=int_(0)^1x^n(1-x)^mdx(m,nin N).4.证明：$\int_{0}^{1}x^{m