Sometimes an x makes no sense to be plugged into a 
   function:
We must steer clear of dividing by 0, 
   or taking even roots of negative numbers.

Chorus: 
   Doh, Domain and Range, we need to understand-
   What can go in, what can come out are part 
      of a function's plan!

We won't deny there are values of y a function cannot 
   put out-
Like negatives from even roots or from absolutes, 
   or 0 from a fraction with nonzero top. 
(Repeat chorus)

And there's no doubt we must leave out values 
   that can't happen:
So we'll ignore a bowling score beyond 0 and 300! 
(Repeat chorus)