Question

Given f(x) = 1/2x - 5, find f^-1(x)

Answer 1

f^-1(x) = 2x + 10 → d

let y = $\frac{1}{2}$ x - 5

rearrange making x the subject

$\frac{1}{2}$ x - 5 = y

add 5 to both sides

$\frac{1}{2}$ x = y + 5

multiply both sides by 2

x = 2y + 10 ⇒ f^-1(x) = 2x + 10

s