00:01
Here, we're given several functions, and we want to find out which ones of these are guaranteed to have an absolute max in min by the extreme value theorem.
00:09
Well, the extreme value theorem says that if a function is continuous over an interval, then it's guaranteed to have a solution.
00:17
And that interval needs to be closed, meaning at the endpoints, it is continuous.
00:24
So, for example, we have the first one, x to the three halves, and we're looking from negative one to one.
00:29
Well, this function is always defined.
00:32
Therefore, it's always continuous.
00:34
So no matter what interval i gave you, this would have an extreme value.
00:39
Now, if i look at the next one, 1 over x to the third.
00:42
Notice we're given the interval from 1 over 4, 1 to 4.
00:46
But it's in parentheses.
00:49
Since it's giving us an open, excuse me, an open interval, then the extreme value theorem isn't telling us anything.
00:56
So these parentheses means that i don't know anything.
01:00
Even though 1 over x cubed is defined in that interval, we're not guaranteed by the extreme value theorem...