Question

If f (x) = one-ninth x minus 2, what is mc003-2.jpg?
mc003-3.jpg
mc003-4.jpg
f Superscript negative 1 Baseline (x) = one-ninth x + 2
f Superscript negative 1 Baseline (x) = negative 2 x + one-ninth

Answer 1

If f(x) = (1/9)x − 2, find f⁻¹(x):

Let y = (1/9)x − 2. Swap x and y: x = (1/9)y − 2. Solve for y:
(1/9)y = x + 2 → y = 9(x + 2) = 9x + 18.

So f⁻¹(x) = 9x + 18. (Check: f(f⁻¹(x)) = (1/9)(9x+18) − 2 = x.)
None of the two text options you listed match; if one of the images is 9x + 18, that is the correct choice.