# numerical integration – NForming: How can I solve this integral numerically? NIntegrate fails while Integrate works

I know that the exact solution of the main value of this integral is equal to zero:

$$int _ {- 1} ^ {1} int _ {- 1} ^ {1} frac {x ^ 2} { sqrt {1-x ^ 2}} frac { sqrt {1-y ^ 2}} {yx} dydx = 0$$

work:

``````To integrate[x^2/Sqrt[1 - x^2] Sqrt[1 - y^2]/ (y - x), {x, -1, 1}, {y, -1, 1},
PrincipalValue -> True]
``````

But I want to do it numerically and it does not work:

``````NIntegrar[x^2/Sqrt[1 - x^2] Sqrt[1 - y^2]/ (y - x), {x, -1, 1}, {y, -1, 1}]
``````

This is the error message returned:

How can I get Mathematics To solve this problem numerically?