00:03
All right, we're given a function x squared minus 10x plus 22 and asked about its domain.
00:09
All right.
00:09
So first thing we want to do is recognize what sort of a function is this.
00:12
The highest exponent is x squared.
00:14
This is just a quadratic function.
00:16
If we were to graph this, we should know that that's going to be some sort of a parabola when we go to graph it.
00:23
All right.
00:23
So the domain is what x values are we allowed? well, i can substitute any x value i want in and get an answer.
00:31
So your domain is going to be all.
00:33
Real numbers, all real numbers.
00:37
Different teachers like to see this in different fashions.
00:41
All real numbers sometimes written out.
00:43
Sometimes teachers will allow you to use that double -backed r, which stands for all real numbers.
00:48
That's just shorthand for it.
00:51
You know, there are different ways.
00:53
Some teachers want to see it as negative infinity to positive infinity with rounded brackets there.
00:59
Negative infinity is less than x is less than than infinity.
01:05
Sometimes they'll even do x such that and kind of write it out like this.
01:10
So make sure you talk to your teacher so that you know exactly what format for the domain your teacher is looking for.
01:17
Just in the off chance that you're actually going to get into doing the range as well, domain and range often go together.
01:25
Let's just do a quick look at this one...