f(x, y) is a continuous function defined over (x, y) ∈ [0, 1] × [0, 1]. Given the two constraints, x > y2 and y > x2, the area under f(x, y) is
1
\(\mathop \smallint \nolimits_{y = 0}^{y = 1} \mathop \smallint \nolimits_{x = {y^2}}^{x = \sqrt y } f\left( {x,\;y} \right)dxdy\)
2
\(\mathop \smallint \nolimits_{y = {x^2}}^{y = 1} \mathop \smallint \nolimits_{x = {y^2}}^{x = 1} f\left( {x,\;y} \right)dxdy\)
3
\(\mathop \smallint \nolimits_{y = 0}^{y = 1} \mathop \smallint \nolimits_{x = 0}^{x = 1} f\left( {x,\;y} \right)dxdy\)
4
\(\mathop \smallint \nolimits_{y = 0}^{y = \sqrt x } \mathop \smallint \nolimits_{x = 0}^{x = \sqrt y } f\left( {x,\;y} \right)dxdy\)