Double Integral

A Multiple Integral with two variables in ${\mathbb{R}}^2$.

Example

${\int }_0^1{\int }_0^y(x^2-2xy+y^2)dxdy$ $={\int }_0^1(\frac{x^3}{3}+x^{2}y+x{y}^2){|}_0^{y}dy$ $={\int }_0^1(\frac{y^3}{3}-y^3+y^3)dy$ $={\int }_0^1(\frac{y^3}{3})dy$ $=(\frac{y^4}{12}){|}_0^1$ $=\frac{1}{12}$