Is this a function

Question

Y=X⁴ +1

Answer 1

It's a function if each value of x corresponds to a single value for y.

y = x⁴ + 1 is a function because if you choose any value for x, there is only one value for x⁴. Add 1 and there is still only one value.

Answer 2

A function means whatever x-value we put in, we'll get only one y-value.

y = √x is not a function because the square roots of say 25 are -5 and 5.

No matter what value we input for x, we get only one y-value, so your equation is a function.

Note: x = -5 and x = 5 will both result in the same y-value, but that doesn't matter. Don't get confused!