(int )_(dfrac {pi )(4)}^dfrac (pi {2)}dtheta (int )_(0)^cot theta (r)^2cos theta f(r)dr= ()A (int )_(dfrac {pi )(4)}^dfrac (pi {2)}dtheta (int )_(0)^cot theta (r)^2cos theta f(r)dr= ()B (int )_(dfrac {pi )(4)}^dfrac (pi {2)}dtheta (int )_(0)^cot theta (r)^2cos theta f(r)dr= ()C (int )_(dfrac {pi )(4)}^dfrac (pi {2)}dtheta (int )_(0)^cot theta (r)^2cos theta f(r)dr= ()D (int )_(dfrac {pi )(4)}^dfrac (pi {2)}dtheta (int )_(0)^cot theta (r)^2cos theta f(r)dr= ()

(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}4(cos )^4theta dtheta =__________________

( 10 ) (int )_(0)^dfrac (pi {4)}(tan )^2theta dtheta ;

5.12 求下列各积分之值:-|||-(1) (int )_(0)^2pi dfrac (dtheta )(a+cos theta )(agt 1);-|||-

9.计算下列积分:-|||-(1) (int )_(0)^2pi dfrac (1)(5+3sin theta )dtheta ;-|||-(2) (int

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

(int )_(0)^dfrac (pi {4)}dfrac (x)(1+cos 2x)dx=( ) .(int )_(0)^dfrac (pi {4)}dfr

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

(5) (int )_(dfrac {pi )(6)}^dfrac (pi {2)}(cos )^2udu;

计算下列积分:-|||-(9) (int )_(-e)^-2dfrac (dx)(1+x);-|||-(10) (int )_(0)^dfrac (pi {4)

当theta =dfrac (pi )(4)时，theta =dfrac (pi )(4)____;当theta =dfrac (pi )(4)时，theta