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(int )_(dfrac {pi )(4)}^dfrac (pi {2)}dtheta (int )_(0)^cot theta (r)^2cos theta
( 10 ) (int )_(0)^dfrac (pi {4)}(tan )^2theta dtheta ;
设=(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}dfrac (sin x)(1+{x)^2}(cos )^4xdx, =(in
当theta =dfrac (pi )(4)时,theta =dfrac (pi )(4)____;当theta =dfrac (pi )(4)时,theta
(int )_(0)^dfrac (pi {4)}dfrac (x)(1+cos 2x)dx=( ) .(int )_(0)^dfrac (pi {4)}dfr
(3) (int )_(0)^dfrac (pi {4)}dfrac (x)(1+cos 2x)dx= () .-|||-(A) dfrac (pi )(8)+
5.12 求下列各积分之值:-|||-(1) (int )_(0)^2pi dfrac (dtheta )(a+cos theta )(agt 1);-|||-
(5) (int )_(dfrac {pi )(6)}^dfrac (pi {2)}(cos )^2udu;
(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}dfrac (|x|sin x)(1+{cos )^3x}dx=(int )_(-
9.计算下列积分:-|||-(1) (int )_(0)^2pi dfrac (1)(5+3sin theta )dtheta ;-|||-(2) (int