If the numerator of an inverse function is not 1, is it still an inverse function?

Question

For example, would still be treated as an inverse function? I'm trying to find its negative intervals, and if it were a regular inverse function (with a 1 as the numerator), I would just find the negative intervals of x2 - 4x - 12 since a second-degree function and its inverse have the same positive/negative intervals. But since the numerator is 5, I'm not sure if that still applies.

I'm sorry if this doesn't make much sense, my math class is in French and I've never taken math in English.

Answer 1

I think you have confused two different uses of the word "inverse."

The inverse of 2/3 is 3/2. Sometimes called the "reciprocal."

The inverse of a function/relation is determined by exchanging the x and the y.

An example

y = x + 2, this is the original

x = y + 2

x - 2 = y, this is the inverse. It may or may not be a function.