Check out the graph of this guy:
f has an absolute and relative min of 0 at x = 2.
So... why is that (4, 4) point nothing? Why isn't there an absolute max there? Well, y = 4 isn't included, so, what would the max be?
See the problem?
|Open endpoints can't be absolute extrema.|
Find the relative and absolute extrema of:
(Yes, you need to graph it!)