What is the inverse of the function f (x) = 1/9x + 2

Solution

Start by substituting y for f (x). That's easier to handle.

y = (1/9) x + 2 Interchange the x and the y. Where you see an x put a y and where you see a y put an x.

x = (1/9) y + 2 Subtract 2 from both sides.

(x - 2) = (1/9) y + 2 - 2

(x - 2) = (1/9) y Multiply both sides by 9

9 (x - 2) = (1/9) y * 9

9 (x - 2) = y You can put the y on the left and the left over on the right.

y = 9 (x - 2) Put f (x) back in

f (x) = 9 (x - 2) This could be the answer. You could also remove the brackets.

y = 9x - 18