I have the following function that I was hoping to simplify in some way
$$\displaystyle f(x,y)=\frac{1+x}{1+y+\sqrt{(1-y)^2+y(1-\frac{1}{x})^2}}$$
defined for $0 < {x,y} \leq 1$ and was wondering whether a convergent multivariate expansion existed over the domain of interest.
Thanks, Tom Waits.