Advertisement

Inverse functions undo each other!

That's it.  Go home.

OK.  I'll elaborate.

Think of a number...  I'll wait.

OK, now add 3 to it...  Now, subtract 3 from that.  What do you get?

The number you started with!

Check it out:

5  ->  + 3  ->  8  ->  - 3  ->  5
 

So, these guys are inverse functions:

f( x ) = x + 3

add the 3 on...

g( x ) = x - 3

takes the 3 off