Question

Find the inverse of f (x) = 3x +5

Answer 1

Inverse of f(x) = 3x + 5 is

`f'(x) = (x-5)/(3)`

Explanation:

Original function is y = f(x) = 3x + 5

To find inverse:

- replace x with y in y = 3x + 5

=> x = 3y + 5

==> 3y + 5 = x (switching sides has no effect)
==> 3y = x - 5 (subtract 5 on both sides)

==>
`y= (x-5)/(3)` (divide by 3 both sides)

Inverse is denoted usually by f'(x) or f⁻1(x)