设 M=int_(-(pi)/(2))^(pi)/(2) (sin x)/(1+x^2) cos^4 x dx，N=int_(-(pi)/(2))^(pi)/(2) (sin^3 x + cos^4 x)dx，P=int_(-(pi)/(2))^(pi)/(2) (x^2 sin^3 x - cos^4 x)dx，则（）

(d)/(dx)int_(sin x)^cos x cos(pi t^2) , dt = ( ). $\frac{d}{dx}\int_{\sin x}^{\c

(4)int_((pi)/(4))^(pi)/(3)(x)/(sin^2)xdx;(4)$\int_{\frac{\pi}{4}}^{\frac{\pi}{3}

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

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

int_(0)^pi/2(cos x+2)dx=( ).A. $\pi+1$B. $\pi$C. 2D. $\pi/2+2$

(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)^dfrac(pi {2)}(|sin x-cos x|{d)x}．计算定积分：$\int_{0}^{\dfrac{\pi }{2}}

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

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

1、int_(-pi)^pix(x^2+5cos x+3)=_1、$\int_{-\pi}^{\pi}x(x^{2}+5\cos x+3)=\_$