∫∫(x^2+y^2)dσ=∫(0,1) dx∫(0,x^2) (x^2+y^2)dy=∫(0,1) x^4+1/3x^6 dx
=1/5x^5+1/21x^7 |(0,1)
=1/5+1/21=26/105