int dfrac ({x)^3}({(1+{x)^2)}^2}dx=A.int dfrac ({x)^3}({(1+{x)^2)}^2}dx=B.int dfrac ({x)^3}({(1+{x)^2)}^2}dx=C.int dfrac ({x)^3}({(1+{x)^2)}^2}dx=D.int dfrac ({x)^3}({(1+{x)^2)}^2}dx=

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

int dfrac ({x)^3}(sqrt {1+{x)^2}}dx,

int dfrac (ln x)({(1+{x)^2)}^3/2}dx; ;

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

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

[题目]-|||-int (dfrac (3)(1+{x)^2}-dfrac (2)(sqrt {1-{x)^2}})dx

int dfrac ({(1-x))^2}(x(1+{x)^2)}dx

(int )_(1)^sqrt (3)dfrac (dx)({x)^2sqrt (1+{x)^2}};

(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}dfrac (|x|sin x)(1+{cos )^3x}dx=(int )_(-

(5) int dfrac (arctan x)(1+{x)^2}dx= __