You have the function:

$F(x, y) = \frac{2xy}{1 - y^2}$

Would you like to find something specific related to this function, such as partial derivatives, its behavior for specific values of $x$ and $y$, or something else? Let me know how I can assist you further!

Related questions:

1. What is the partial derivative of $F(x, y)$ with respect to $x$?
2. What is the partial derivative of $F(x, y)$ with respect to $y$?
3. How does the function $F(x, y)$ behave as $y$ approaches 1 or -1?
4. What is the limit of $F(x, y)$ as $y \to 1$?
5. How can we find the critical points of $F(x, y)$?

Tip:

When dealing with rational functions like this one, it's important to note the domain, as values where the denominator is zero (like $y = \pm 1$) would make the function undefined.