The cool stuff happens when we get more terms in there!
Pop this guy into a graphing calculator:
Your graph should look about like this:
|THINGS TO NOTICE:|
Both tails shoot up.
In Precalculus, you were mostly concerned with finding where these cross or touch the x-axis -- because, really, that's all you COULD easily find without Calculus.
Now, we'll be more interested in the mountains and valleys, where the graph is going up and down and what those tails are doing.