v=∫∫f(x,y)dσ区域D=∫（0-4）dx∫(0-4)x^2+y^2+1dy=∫(0-4)dx(x*x*y+1/3y*y+y)|(4-0)=∫(0-4)(4*x*x+76/3)dx=(4/3x^3+76x/3)|(4-0)=560/3注：“（0-4）”为x,y的区域,“|（4-0）”为消去积分后分别带入4和0作差....