Question

Is there a difference between writing f(x), g(x), h(x)? Do the letters f, g, h, etc. have any significance?

Answer 1

No. They have no special significance.

Explanation:

All of these are simply used by convention to refer to a function. For example, `f(x)=e^x`, `a(x)=e^x`, and `z(x)=e^x` all mean the same thing.

However, some notations mean only one thing. For example, `zeta(s)` refers to the Riemann zeta function:
`sum_(n=1)^oo1/n^s`
(See this link for more info: Riemann zeta function)

In general, though, functions that describe one particular equation (like the Riemann zeta function) use Greek letters instead of normal English characters.

And the variable `z` generally refers to multi-variable functions, such as `z=xy`.

I'm sure others can add more to this question, so I invite further answers/comments.