inverse function

`f^-1 (x)` = Reverse function (`x`)

`f^-1` = Reverse machine

`x` = input

Note: `f^-1` is not a power (or exponent). It means reverse the machine.

`f^-1 (x)` reverses or undoes what the original function did.

It means the reverse.

1 a. `f (x) = 2x + 3`

Then this machine "`f`" takes the input `x` multiplies by 2 and add 3.

Then this machine "`f^-1`" subtracts 3 from the input `x` and then divides it by 2.

2 a. `f (x) = (5x - 3)/4`

Then this machine `f` takes the input `x` multiplies by 5, then takes away 3 and then divides by 4.

2 b. `f^-1``(x) =(5x - 3)/(4)`

Then this machine `f^-1` multiplies the input `x` by 4 then adds 3 and then divides by 5. (i.e. a reversal of the above).

`f^-1``(x) = (4x + 3)/5`