00:01
All right, so once again, this idea for this question, number 14, did come up in previous problems, but if you didn't watch the videos for numbers 1 through 12, or you want a more clear answer, this is when we use brackets.
00:18
We use brackets whenever the boundary value is included in the solution set.
00:24
And so you'll notice that i've already answered number 13 here with four different options.
00:29
We have the greater than, less than, greater than or equal to, less than or equal to symbol.
00:34
And you can see i put anywhere where there are parentheses involved.
00:38
Parentheses are involved whenever you do not include the boundary.
00:43
So infinity or negative infinity, you can't include it.
00:47
And then the open circles, which come from having less than or greater than, but not less than or greater than or equal to.
00:57
So brackets come in whenever you include a specific point in your boundary, either because you have two boundaries and they're both included...