$\displaystyle f(x) = 1/4x - 4 ,

-3 < x < 1 (theyre both equal as well as less than)

$

And it's asking to find the interval of [A,B].

I know how to find the inverse of the function, and I also know that the range of the function f(x) would be the domain of the inverse. However I don't know how to find that out.