# Thread: Inverse of function

1. ## Inverse of function

Hey guys.

I've got this function: $f(x,y) = (x, y^3 +xy)$

I need to find the inverse of this function. How would I go about that? I know how to do it, when the function consists of one variable, but what do I do, when it has two variables?

Thanks for the help.

Morten

2. ## Re: Inverse of function

Originally Posted by m112358
I've got this function: $f(x,y) = (x, y^3 +xy)$ . I need to find the inverse of this function. How would I go about that?
Supposing $f^{-1}$ exists, in general we can't explicitly determine it. For example, denote $(u,v)=(x,y^3 +xy).$ Then, $x=u$ and $y^3+uy=v.$ Could you get a reasonable expression $y=y(u,v)$ ?