What if we try sticking a negative number in?

-3  ->  ( )^2  ->  9  ->  square root( )  ->  3

A -3 went in... but, a 3 came out!  These don't work for negative numbers.  So, for this one, we have to say

These are inverse functions only when x is greater than or equal to 0  :

f( x ) = x^2

g( x ) = square root( x )

(This will be even clearer later.)

The official notation for the inverse function of a guy named f(x) is

(f^( -1 ))( x)

(read as "f inverse of x.")

* The little "-1" is NOT an exponent!  It's just a notation.  Hey -- they didn't ask ME about this stuff when they made it up!

I know you're really excited about this...  But, you don't know enough to try any problems yet.  Keep reading!