Graph these and remember to identify what's going on -- and not by plotting points.  Be sure to label 5 points like a polite math geek:

y = x^2 + 2

y = x^2 - 1

Let's sum up what we've got here:

When there's a number hanging off the end of Standard Parabola Guy...

It's a vertical shift!

y = x^2 + k

He moves up if k is positive.
He moves down if
k is negative.


Check out this animation for a little review: