Question

which statement correctly explains whether the equation $y = x^2 - 2$ represents a function?
it is a function because there is only one $x$-value for each $y$-value.
it is a function because there is only one $y$-value for each $x$-value.
it is not a function because there are no $y$-values less than $-2$.
it is not a function because $y = 2$ when $x = 2$ or $x = -2$.

Explanation:

A relation is a function if every input (x-value) has exactly one output (y-value). For the equation $y = x^2 - 2$, substituting any single x-value will result in only one corresponding y-value. Multiple x-values can map to the same y-value, which does not violate the function definition.

Answer:

B. It is a function because there is only one y-value for each x-value.