If you have

I know f(x) just means the function of x, or just y.

But take this:

If

then

Where r= remainder

(Headbang) This makes no since to me. some function divided by x-k yields the function of k.

How do you come up with a function? (Crying)

Edit: normally f(x),f(c),f(g) are all put in the place of possible functions, but this one is not.