y=1,x=±1
∫∫x^2+3xy^2dxdy =∫dx∫[x²+3xy²]dy
=∫dx [x²y+xy³]|
=∫dx [x²+x-x^4-x^7 ]
=[x³/3+x²/2-x^5/5- x^8/8]|
=2/3-2/5=4/15