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}}
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. $\pi/2+2$
15.计算定积分I=int_(1)^3|x-2|dx.15.计算定积分$I=\int_{1}^{3}|x-2|dx$.
17.计算定积分int_(0)^sqrt(2)(x^2)/(sqrt(4-x^2)) dx.17.计算定积分$\int_{0}^{\sqrt{2}}\frac{
2.计算定积分int_(0)^1ln(1+sqrt(x))dx.2.计算定积分$\int_{0}^{1}\ln(1+\sqrt{x})dx$.
(int )_(0)^dfrac (pi {4)}dfrac (x)(1+cos 2x)dx=( ) .(int )_(0)^dfrac (pi {4)}dfr
14、计算定积分int_(1)^e(ln^2x)/(x)dx.14、计算定积分$\int_{1}^{e}\frac{\ln^{2}x}{x}dx$.
计算定积分 int_(0)^pi sin xdx= ( )A. 1B. -1C. 2D. -2
(d)/(dx)int_(sin x)^cos x cos(pi t^2) , dt = ( ). $\frac{d}{dx}\int_{\sin x}^{\c