Question

Find an expression for f−1(x), if f(x) = 5 − 2x

Answer 1

Answer:

$f^{-1}$(x) = $\frac{5-x}{2}$

Step-by-step explanation:

Let y = f(x) and rearrange making x the subject

y = 5 - 2x ( add 2x to both sides )

2x + y = 5 ( subtract y from both sides )

2x = 5 - y ( divide both sides by 2 )

x = $\frac{5-y}{2}$

Change y back into terms of x

$f^{-1}$ (x) = $\frac{5-x}{2}$