Question

if f(X)=1/9x-2, what isf-1(x)?

Answer 1

The way I would solve this problem would be replacing f(x) with y.
This would give you y=1/(9x -2)
Then you would switch y's and x's giving you x=1/(9y-2).
Now if you solve for the new y, it will give you f-1(x).
I will solve it out for you.
x(9y-2)=1
9y-2=1/x
9y=1/x +2
Answer: y=1/(9x)+2/9 or f-1(x)=1/(9x)+2/9
Note: I am not sure if you intended f(x) to be 1/(9x-2), 1/(9x) -2