# 1.5.2 Inverse Function Example 4 – 6

Example 4:
(a) If f : xx – 2, find f -1 (5),

Solution:

(a)
f (x) = x– 2
Let y = f -1 (5)
f (y) = 5
y – 2 = 5
y = 7
therefore, f -1 (5) = 7

(b)

Example 5

If $g:x↦\frac{m-x}{x-3},x\ne 3$   and ${g}^{-1}\left(5\right)=14$  .  Find the value of m.

Correction:
m – 14 = 55
m = 55 + 14
m = 69

Example 6 (Comparison Method)
If $f:x↦\frac{mx-n}{x-2},x\ne 2$   and ${f}^{-1}:x↦\frac{5-2x}{2-x},x\ne 2.$ . Find the value of m and of n,

### 2 thoughts on “1.5.2 Inverse Function Example 4 – 6”

1. the final answer of b is 12 right？

• Dear Aini,
Thanks for pointing out our mistake.
Correction was done accordingly.