(15)(int )_(0)^pi xsqrt ({cos )^2x-(cos )^4x}dx= __

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

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

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

(int )_(0)^2xsqrt (2x-{x)^2}dx= __

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

(int )_(-dfrac {pi )(2)}^dfrac (pi {2)}((cos )^2x+dfrac (xcos x)(1+{cos )^2x})dx

例: (int )_(0)^dfrac (pi {2)}(cos )^2dfrac (x)(2)dx= __ .

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

15.不定积分 int cos (3x-dfrac (pi )(4))dx=

(3) (int )_(0)^dfrac (pi {4)}dfrac (x)(1+cos 2x)dx= () .-|||-(A) dfrac (pi )(8)+