| Rule |
 |
These guys in the set are just
like (
x ,
y )
points on a graph...
So, we can
actually graph this thing:
 |
* Don't connect the dots!
These are isolated points and
this isn't a coloring book! |
Just like before,
the x
guys are our input guys --
the domain:
And remember that
y
guys are really
f(x)
guys --
range guys:
OK, so how can I
tell if this guy is a function or not? There are two ways:
The vertical line test (which we'll stick with) and another way
that uses cool domain and range blobs (which you'll probably see
if you go on to take some harder courses in math.)
Here's the
vertical line test way -- but, now I want to be sophisticated
and use the official definition:
 |
Yes,
R
is a function since each
element in the domain goes to
exactly one element in the range.
(It passes the vertical line test.) |
