How do you know of an exponential fuction is reflected across the x-axis?​

Step-by-step explanation:

A reflection over the x-axis changes all the y-values. The reflection is modeled as -f(x)

For example:

would look like -- .

If the negative sign is outside of the bracket ( what it's called sorry), then it is a reflection over the x-axis

However if the negative sign was inside the bracket: then this would be a reflection over the y axis.

Hope this helps!