int dfrac ({e)^x}({2)^x}dx;

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

设 int dfrac (f(x))(x)dx=(e)^x+C ，则int dfrac (f(x))(x)dx=(e)^x+Cint dfrac (f(x))(

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

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

(9) int dfrac (x{e)^arctan x}({(1+{x)^2)}^dfrac (3{2)}}dx ;

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

int (e)^-2xsin dfrac (x)(2)dx; ;

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

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

不定积分int dfrac (dx)(4{x)^2-9}=-|||-__.int dfrac (dx)(4{x)^2-9}=-|||-__int dfrac (