My function is $f(x,y)=xy\frac{x^{2}-y^{2}}{x^{2}+y^{2}}$ EDIT defined $f(0,0)=0$ (How does that impact the evaluation of partial derivatives?)
I need to evaluate the function at $f_{xy}(0,0)$ and similarly for $f_{yx}(0,0)$ My problem is that upon evaluating the function at (0,0), I get cases of $0/0$ How can I get around it? Should I try rearranging terms with algebra?