Thus, the partial derivatives are:
\[
\frac{\partial f}{\partial x} = \frac{y}{\sqrt{-x^2y^2 + 1}}, \quad \frac{\partial f}{\partial y} = \frac{x}{\sqrt{-x^2y^2 + 1}}
\]
The final boxed answers are:
\[
\boxed{\frac{\partial f}{\partial x} = \frac{y}{\sqrt{-x^2y^2 + 1}}}
\]
\[
\boxed{\frac{\partial f}{\partial y} = \frac{x}{\sqrt{-x^2y^2 + 1}}}
\]