Question

Explain why y^2 = x (X input, y output) is not a function.

Answer 1

Not a function because it can’t be put into y=mx+b form.

Answer 2

y^2 = x isn't a function because there is at least one value of x that produces multiple values of y. In fact, any x value greater than 0 yields two y values. If x = 0, then y = 0 is the only solution. ... Graphically, the equation fails the vertical line test, which is another way to determine that it is not a function.