As far as I know, there is no such function. Unless I am missing something.
You are probably using a UDF (user defined function). This you can find by
doing the following: Tools > Macro > Visual basic editor. Click on modules
in the left and see if such a function exists.
Function Quadratic()
End Function
If it exists, you could post it, and if it doesn't then you won't be able to
use it.
Mangesh