Question

将二重积分化为二次积分∫∫f(x,y)dxdy其中D是由y=x,y=x+1,x=0和x=1确定

Answer 1

（1）∫∫f(x,y)dxdy=∫dx∫f(x,y)dy (先积分y,再积分x) =∫dy∫f(x,y)dx+∫dy∫f(x,y)dx (先积分x,再积分y)；（2）∫∫f(x,y)dxdy=∫dy∫f(x,y)dx (先积分x,再积分y) =∫dx∫f(x,y)dy+∫dx∫f(x,y)dy (先积分y,再积分x).

追问

这就一道题啊