Question

let f(x) = 2x − 6. solve f−1(x) when x = 2.

Answer 1

f(x) = 2x - 6

y = 2x - 6
2x - 6 = y  |add 6 to both sides
2x = y + 6    |divide both sides by 2
x = 1/2y + 3

f^{-1}(x) = 1/2x + 3

f^{-1}(2) = 1/2 · 2 + 3 = 1 + 3 = 4