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

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

(15)int (x)^3(ln )^2xdx;

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

(9) int xtan^2xdx;(9) $\int x\tan^{2}xdx;$

定积分int_(0)^(pi)/(4)sec^2xdx=11.（填空题，5.0分）定积分$\int_{0}^{\frac{\pi}{4}}sec^{2}xdx=

定积分 (int )_(1)^2xdx=(x)^2+C ( ) ○正确 ○错误定积分( )○正确 ○错误

(int )_(-infty )^+infty (x)^2(e)^-a(x^2)dx=dfrac (1)(2)sqrt (dfrac {pi )({a)^3}}

定积分(int )_(0)^3(2)^xdx=( ).A.(int )_(0)^3(2)^xdx=B.(int )_(0)^3(2)^xdx=C.(in

[例3] (int )_(0)^+infty dfrac (x{e)^-x}({(1+{e)^-x)}^2}dx

[题目]计算: (int )_(-2)^2sin 2xdx= __