发布网友 发布时间:2024-10-24 15:05
共1个回答
热心网友 时间:2024-11-05 08:07
D={(x,y)|0≤x≤1, x^2≤y≤√x}
∫∫(D)(x^2+y)dσ
=∫(x:0→1)dx∫(y:x^2→√x)(x^2+y)dy
=∫(x:0→1)[x^2*y+y^2/2]|(y:x^2→√x)*dx
=∫(0→1)[(x^2*√x+x/2)-(x^2*x^2+x^4/2)]*dx
=∫(0→1)[x^(5/2)+x/2-(3/2)x^4]dx
=[(2/7)x^(7/2)+(1/4)x^2-(3/10)x^5]|(0→1)
=2/7+1/4-3/10
=33/140