In order to determine a function's inverse, solve for x and then switch the x and y.
`f(x) = 2x + 6`
Substitute y for f(x): `y = 2x + 6`
Solve for x.
`y = 2x + 6`
`y - 6 = 2x` Multiply by `1/2` to isolate x.
`1/2(y - 6) = x` Switch x and y.
`1/2(x-6) = y`
or `y = 1/2(x - 6)`
Since `g(x) = 1/2(x-6)` then the 2 functions are inverses.