(4)int_((pi)/(4))^(pi)/(3)(x)/(sin^2)xdx;

设 M=int_(-(pi)/(2))^(pi)/(2) (sin x)/(1+x^2) cos^4 x dx，N=int_(-(pi)/(2))^(pi)/(

10 若 f(x)= int_(0)^2xf((t)/(2))dt+4, 则 int_(0)^pi f(x) sin xdx= ___.10 若 $f(x)=

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

(15)int_(-(pi)/(2))^(pi)/(2)sqrt(cos x-cos^3)xdx;(15)$\int_{-\frac{\pi}{2}}^{\fr

计算定积分 int_(0)^pi sin xdx= ( )A. 1B. -1C. 2D. -2

定积分int_(0)^(pi)/(4)sec^2xdx=11.（填空题，5.0分）定积分$\int_{0}^{\frac{\pi}{4}}sec^{2}xdx=

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

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

当 x > (pi)/(2) 时，int_((pi)/(2))^x ((sin t)/(t)) , dt = ( )A. $\frac{\sin x}{x}$

(int )_(0)^dfrac (pi {4)}(tan )^2xdx=1-dfrac (pi )(4) __-|||-__下列式子或叙述不正确的是A.B.设