(int )_(e)^+infty dfrac (dx)(x{ln )^2x}= __

求不定积分int dfrac (1)(2x)sqrt (ln x)dx=（）.int dfrac (1)(2x)sqrt (ln x)dx=int dfrac

int dfrac (1)(x{ln )^2x}dx

()-|||-(2) (int )_(-infty )^+infty dfrac (2x)(1+{x)^2}dx=lim _(aarrow +infty )(i

( 单选题 ) int dfrac ({e)^x}(1+{e)^2x}dx=_________int dfrac ({e)^x}(1+{e)^2x}dx=int

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

(int )_(1)^(e^2)dfrac (ln x)(sqrt {x)}dx= __

二、计算 (int )_(0)^+infty (e)^-2x|sin x|dx

(int )_(0)^+infty dfrac (x{e)^-x}({(1+{e)^-x)}^2}dx= ()-|||-__

[题目]求 int dfrac (arctan {e)^x}({e)^2x}dx

(int )_(-infty )^+infty dfrac (dx)({x)^2+2x+2}..