This may look like an afterthought, since I'm sticking it at the end, but, it isn't. This stuff is really important -- I just didn't want to interrupt the flow of the zeros lessons.
Check out this graph:
You've got an ant climbing on the graph. Not just any ant... Pierre the Mountain Climbing Ant!
(He's kind of a pathetic math superhero.) For this, the rule is that Pierre only crawls from let to right (like we read):
If Pierre is climbing uphill, then the graph is increasing:
So, our graph is increasing on
(we use interval notation with X VALUES!)