f(x) = (x+3)^2 what is f?

Question

If you have f(x) = (x+3)^2 what is f? should you have to take it back or is there not enough information.

Answer 1

f is just an arbitrary name for a function. The equation is a definition of the function called f, just as x is an arbitrary name for a variable. f(x) tells us that the function is going to be defined in terms of a variable called x. x is a placeholder for any value so that, for instance, f(6) would plug 6 wherever x appears in the definition of the function.