One of the main things you'll be hunting in Calculus is where graphs are increasing and decreasing...  So, we'd better review it!

Check out this graph:

a graph

You've got an ant climbing on the graph.  Not just any ant...  Pierre the Mountain Climbing Ant!

Pierre the Mountain Climbing Ant!!

(He's kind of a pathetic math super hero.)  For this, the rule is that Pierre only crawls from left to right (like we read):

Pierre always walks from left to right

If Pierre is climbing uphill, then the graph is increasing:

on the intervals ( -infinity , -3 )  U  ( 1 , 4 ) Pierre is climbing uphill  ...  therefore the graph is increasing

So, our graph is increasing on

( -infinity , -3 )  U  ( 1 , 4 )

(We use interval notation with X VALUES!)