∫∫(y/x)dxdy
=∫dx∫(y/x)dy+∫dx∫(y/x)dy
=∫1/2(x-x^5)dx+∫1/2(x^5-x)dx
=1/2(x²/2-x^6/6)|+1/2(x^6/6-x²/2)|
=1/6+1/6
=1/3