∫∫（x∧2+y∧2）dxdy,其中D为y=x,y=0及x=1 =∫{0到1}dx∫{0到x}(x∧2+y∧2)dy =∫{0到1}dx*[x∧2*y+(1/3)y∧3|{0到x} ] =∫{0到1}(4/3)x∧3dx =(1/3)x∧4|{0到1} =1/3