Pre-Calculus Help (Functions)?

Question

Determine whether the equation defines y as a function of x.

y= x^2 (are you supposed to solve for x first or for y?)

Answer 1

y = x^2

y actually is a function of x, in that any value of x yields a single value of y (this is the definition of function);

on the contrary, if you solve the equation for x, you don't get a function:

in fact:

x^2 = y →

x = ±√y

and therefore any y-value yields two opposite x-values (and not just a single value)

I hope it helps...

Bye!