(9) (int )_(-dfrac {pi )(2)}^dfrac (pi {2)}|sin x|arctan (e)^xdx

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

定积分(int )_(0)^dfrac (pi {2)}(e)^xsin xdx的值是(int )_(0)^dfrac (pi {2)}(e)^xsin xdx

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

( (int )_(dfrac {pi )(4)}^dfrac (pi {3)}dfrac (x)({sin )^2x}dx ;

(6) (int )_(0)^dfrac (pi {2)}(sin )^2xcos xdx;

[题目]计算定积分: (int )_(-dfrac {pi )(2)}^dfrac (pi {2)}((|x|+sin x))^2dx

设(X,Y)的分布函数为(x,y)=dfrac (1)({pi )^2}(dfrac (pi )(2)+arctan dfrac (x)(2))(dfrac (

(int )_(0)^dfrac (pi {2)}(e)^2xcos xdx

(int )_(0)^dfrac (pi {2)}(e)^2xcos xdx; ;

[题目]计算定积分: (int )_(-dfrac {pi )(2)}^dfrac (pi {2)}dfrac (1)(2)xcos xdx.