Question

What does the notation f(2) mean?

Answer 1

the output (y-value) when x=2

Answer 2

The expression "f(x)" means "plug a value for x into a formula f "; the expression does not mean "multiply f and x"! Don't embarrass yourself by pronouncing or thinking of "f(x)" as being "f times x". In notation, the "x" in "f(x)" is called "the argument of the function", or just "the argument".