269 int_(0)^1dyint_(y)^1sqrt(x^2)-y^(2)dx的值为A. $\frac{\pi}{3}$.B. $\frac{\pi}{6}
五.计算积分int_(-1)^1dyint_(1+sqrt(1-y^2))^sqrt(2-y^(2))(sqrt(x^2)+y^(2)+sin^3y)dx五.(
17.计算int_(1)^2dyint_(sqrt(y-1))^1(sin x)/(x)dx.17.计算$\int_{1}^{2}dy\int_{\sqrt{y
设 iint_(D) f(x, y)dx dy = int_(0)^1 dx int_(0)^1-x f(x, y)dy，则改变其积分次序后为A. $\int_
定积分 int_(0)^1 (1)/(1 + sqrt(x)) dx = ( )A. $1 - 2\ln 2$B. $2 - \ln 2$C. $2 - 2\l
【例4】已知函数f(x)在[-1,2]上连续，且int_(-1)^0f(x)dx=2，int_(0)^1f(2x)dx=1，则int_(-1)^2f(x)dx=
积分 int_(0)^1 xe^2x , dx = ____.A. $\frac{e^2+1}{4}$B. $1$C. $\frac{e^2+1}{2}$D.
广义积分int_(1)^+infty(1)/(x^2)dx=（）A. 0B. 1C. -1D. 3
设int_(-1)^13f(x)dx=18，int_(-1)^3f(x)dx=4，int_(-1)^3g(x)dx=3。则int_(-1)^3(1)/(5)[4
已知 f(x)在 [1, 4] 可导, f(4)= 1, int_(0)^4 xf(x), dx = 3，则 int_(0)^4 f(x), dx = (