Question

if ƒ is a one to one and ƒ(4)=8,

then ƒ-1(8)= 4 but how do i get the ƒ(4)-1=?

I know

Answer 1

If f(x) is one-to-one, the implication is that f(x) has an inverse function, which we denote by \[f ^{-1}(x)\]

Answer 2

if you are given (x,y) [ which here are (4,8) }, you can evaluate the inverse function at y very easily:

Starting with f(4)=8,
reverse the order, replacing f with \[f ^{-1}(x)\] your result should be \[f ^{-1}(8)=4\]

Answer 3

It's really that simple. But you must understand the relationship between f(x) and its inverse \[f ^{-1}(x)\]

Answer 4

and know how to find the inverse function from f(x).