- 求答求∫∫(x+2y)dxdy,D由抛物线y=2x^2和y=1+
- 求∫∫(x+2y)dxdy,D由抛物线y=2x^2和y=1+x^2围成
- ∫∫(x+2y)dxdy
=∫<-1,1>dx∫<2x^2,1+x^2>(x+2y)dy
=∫<-1,1>[x(1+x^2)+(1+x^2)^2-2x^3-4x^4]dx
=∫<-1,1>[x-x^3+1+2x^2-3x^4]dx
=[x+(1/2)x^2+(2/3)x^3-(1/4)x^4-(3/5)x^5]|<-1,1>
=2+4/3-6/5
=32/15.