# Thread: Y a function of X?

1. ## Y a function of X?

Could someone please assist and advise if the following equation determines Y to be a function of X : y2 = x + 3 ? (the 2 is an exponent) Thanks much!

2. Originally Posted by jay1
Could someone please assist and advise if the following equation determines Y to be a function of X : y2 = x + 3 ? (the 2 is an exponent) Thanks much!
Hi jay1,

If $y^2=x+3$, then $y=f(x)=\pm \sqrt{x+3}$

$f(x)=\pm \sqrt{x+3}$ is a parabola with vertex on the x-axis and opening to the right. By definition, it is not a function.