Question

计算二重积分D∫∫x^2dxdy,其中D是曲线y=1/x,直线y=x,x=2及y=o所围平面区域

Answer 1

∫∫x^2dxdy=∫x^2dx∫dy+∫x^2dx∫dy
=∫x^3dx+∫xdx
=1/4+(2^2-1)/2
=7/4.