A. $\frac{2}{3}-\frac{\pi}{4}$
B. $\frac{2}{3}+\frac{\pi}{4}$
C. $\frac{2}{3}+\frac{\pi}{8}$
D. $\frac{2}{3}-\frac{\pi}{8}$
【例7.16】已知函数f(t)=int_(1)^t^(2)dxint_(sqrt(x))^tsin(x)/(y)dy,则f((pi)/(2))=____.【例7
在下列积分中改变累次积分的顺序:-|||-(1) (int )_(0)^2dx(int )_({x)^2x}f(x,y)dy;-|||-(2) (int )_(
设 M=int_(-(pi)/(2))^(pi)/(2) (sin x)/(1+x^2) cos^4 x dx，N=int_(-(pi)/(2))^(pi)/(
五.计算积分int_(-1)^1dyint_(1+sqrt(1-y^2))^sqrt(2-y^(2))(sqrt(x^2)+y^(2)+sin^3y)dx五.(
3.设I=int_(0)^1dxint_(0)^x^(2)f(x,y)dy+int_(1)^2dxint_(0)^2-xf(x,y)dy，则交换积分次序后，I可
(int )_(-pi )^pi sqrt ({pi )^2-(x)^2}dx= )(int )_(-pi )^pi sqrt ({pi )^2-(x)^2}d
计算定积分：int_(0)^dfrac(pi {2)}(|sin x-cos x|{d)x}．计算定积分：$\int_{0}^{\dfrac{\pi }{2}}
(2)(dy)/(dx)+(y)/(x)=(sin x)/(x),y|_(x=pi)=1;(2)$\frac{dy}{dx}+\frac{y}{x}=\frac
(int )_(0)^dfrac (pi {2)}sqrt (1-sin 2x)dx;
1.积分int_(0)^1dxint_(x)^1e^-y^(2)dy的值是____1.积分$\int_{0}^{1}dx\int_{x}^{1}e^{-y^{2