Answer
$$0$$
Work Step by Step
$$\eqalign{
& \int_0^1 {\int_{ - \sqrt {1 - {x^2}} }^{\sqrt {1 - {x^2}} } {2{x^2}y} dy} dx \cr
& {\text{Integrate with respect to }}y \cr
& = \int_0^1 {\left[ {{x^2}{y^2}} \right]_{ - \sqrt {1 - {x^2}} }^{\sqrt {1 - {x^2}} }dx} \cr
& {\text{Evaluating}} \cr
& = \int_0^1 {\left[ {{x^2}{{\left( {\sqrt {1 - {x^2}} } \right)}^2} - {x^2}{{\left( { - \sqrt {1 - {x^2}} } \right)}^2}} \right]dx} \cr
& {\text{Integrate with respect to }}x \cr
& = \int_0^1 {\left[ {{x^2}\left( {1 - {x^2}} \right) - {x^2}\left( {1 - {x^2}} \right)} \right]dx} \cr
& = \int_0^1 {\left( {{x^2} - {x^4} - {x^2} + {x^4}} \right)dx} \cr
& = \int_0^1 {0dx} \cr
& = 0 \cr} $$