Question

Is
f(x)
f(n)
f(a number)
Does all of them mean y?

Answer 1

Technically, yes

You can think of ‘f’ as standing for ‘function’, which means the graph

So when you have f(x), it means ‘the value of the function at x’, which is always the y value because (x,y) is a point

So yes, f(x) and f(n) mean y

With f(a number) it means more specifically y at that number

So: f(6) means the value that y is a 6
So if f(6)=7 that would mean the point is (6,7) because when x is 6 y is 7