How do I simplify this function so that I am able to sketch it and obtain the domain?

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I have a function: $f(x,y) = y^2 + \ln(x^2) -1$.

I need to sketch this function and use the sketch to obtain the domain of the function, however, I cannot sketch the function if it is in the form given above, I need to simplify/rearrange it into to something I can sketch.

This is where I am having some issues. I'm not sure how I can simplify the above into something I can sketch, the only simplification I can see possible is to change $\ln(x^2)$ to $2\ln(|x|)$ but I don't think this helps.

Any suggestions on what simplification I could make or what process I would need to do to be able to sketch this function?

Thanks in advance

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I'd say in this case it is easier not to sketch this function, but to look at this algebraically. The function $g(y)=y^2$ is defined for all $y \in \mathbb{R}$. The function $h(x)=\ln(x^2)$ is well-defined if $x^2>0$, i.e. if $x \neq 0$. Since $f(x,y) = g(y)+h(x)-1$, your function is well-defined for all $(x,y) \in (\mathbb{R}\setminus\{0\}) \times \mathbb{R}$, so that is your domain.