00:03
In this problem, we're giving a graph and we wanted to write the domain and range of the graph in interval notation.
00:09
So as a reminder, when we have interval notation, you have parentheses and brackets.
00:17
We're writing it.
00:18
So remember, for interval notation, you use parentheses of brackets, not any quality symbols.
00:26
So let's review.
00:28
Parentheses are used when you have an infinity symbol or not.
00:36
Negative infinity symbol or when you have an open circle, all right? because remember the parentheses mean that it's getting close to the value, but it doesn't actually reach that value.
00:51
So that's when we use the open, the parentheses for open circle on the graph or we have infinities.
00:58
And the brackets are used when you have closed circle.
01:08
So definite values that we know the graph does reach.
01:14
So let's review domain and range.
01:17
Domain remember that's all possible x values so all possible x values are the domain and all possible y values are the range all possible x's and range is all possible y's now what i think will be helpful when you're doing domain and range is to just highlight what you've been given so for example domain is related to the x's and range is related to the y's so what i like to encourage you to do is look at where the graph starts for the domain.
02:03
So we're going to look at where the graph starts.
02:04
The graph starts at this point here and it ends at this point over here.
02:10
So we want to know what x values correspond to those points, okay, because that's beginning and end.
02:18
So all we have to do is basically take our graph and line those points up with the x axis for the domain.
02:33
So we see it starts.
02:35
At negative 2 and it ends at positive 4.
02:40
And if you notice, you have an open circle at the end...