int 1(e)^-2tdt-|||-.(int )_(1)^2xdx.-|||-.fxsin xcos xdx.-|||-15. int (x)^2(cos )^2dfrac (x)(2)dx.-|||-16. int xln (x-1)dx.-|||-17. int ((x)^2-1)sin 2xdx.-|||-18. int dfrac ({ln )^3x}({x)^2}dx.-|||-.(int )_(0)^sqrt [3](x)dx.-|||-.int cos ln xdx.-|||-21. int ((arctan x))^2dx.-|||-22.|e^xsin^2 xdx-|||-23.|xln^2xdx.-|||-24. int (e)^sqrt (3x+9)dx

int t(e)^-2tdt.-|||-.int (ln )^2xdx-|||-.int xsin xcos xdx.-|||-15. int (x)^2(co

int (x)^2cos xdx.-|||-12. int t(e)^-2tdt..-|||-13.|nn^2xdx.-|||-.fxsin xcos xdx.

int ((x)^2-1)sin 2xdx.-|||-18. int dfrac ({ln )^3x}({x)^2}dx.

填空:-|||-(1) int (x)^3(e)^xdx= __ ;-|||-(2) int dfrac (x+5)({x)^2-6x+13}dx= __

[题目] int (cos )^2dfrac (x)(2)dx= __

设=(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}dfrac (sin x)(1+{x)^2}(cos )^4xdx, =(in

(int )_(1)^2dfrac (dx)(x(1+sqrt {2x))}=( )A.(int )_(1)^2dfrac (dx)(x(1+sqrt {2x

9.int x(cos )^2dfrac (x)(2)dx9.

(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}((cos )^2x+dfrac (xcos x)(1+{cos )^2x})dx

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