int (x)^2arctan xdx; ;
(1) int (x)^2arctan xdx;
(18)int x^2arctan xdx.(18)$\int x^{2}\arctan xdx$.
28、 dfrac (d)(dx)(int )_(1)^2arctan xdx= __-|||-_
13.计算不定积分 int dfrac ({x)^2arctan x}({x)^2+1}dx
(9) (int )_(-dfrac {pi )(2)}^dfrac (pi {2)}|sin x|arctan (e)^xdx
② lim _(xarrow 0)(x)^2arctan dfrac (1)(x);
(int )_(0)^+infty x(2)^-xdx=( )(int )_(0)^+infty x(2)^-xdx=( )(int )_(0)^+inft
(19) int tan sqrt (1+{x)^2}cdot dfrac (xdx)(sqrt {1+{x)^2}}-|||-(20) int dfrac (
(19) int tan sqrt (1+{x)^2}cdot dfrac (xdx)(sqrt {1+{x)^2}}-|||-(20) int dfrac (