Alright! So, your answer is: never a function.
First thing first, let's visualize what a graph symmetric to the x-axis looks like.
Take a look at the first attachment.
Pretty clear, it's symmetric across the x-axis.
To figure out if something is a function or not, use the vertical line test! What you do, is run a vertical line down the graph. Does it eventually give you more than one point? Then it's not a function.
Take a look at this the second attachment.
The vertical line intercepts in 3 different points at once on the top picture. Therefore, it is not a function.
If you're ever uncertain, try the vertical line test. :>
I haven't used brainly in a long while, so pardon if the attachments are a little wonky.
