what is means by $ f(n)$

Question

in this question bellow, it write like this:

Please create a program to find $ f(n)$ .

Anyone who could tell me, what does $ f(n)$ means??

Answer 1

I don't know your context, but those dollar signs are used by LaTeX for example to typeset f(n) in math mode.
For you, this would mean that you can safely ignore the $s and concentrate on f.