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Alright, real quick, I just want to go through, remind you guys what function notation is
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so that you can always remember how to determine if a line or set of points is a function
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or not.
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First of all, we have a set of our x and y coordinates and they're labeled on this
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table.
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First thing you remember are domain is always our set of our x coordinates.
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So therefore domain is going to be obtained, negative 2, 2, 3 and 4.
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The domain remembers always the x coordinates.
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Our range is going to be our set of our y coordinates.
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We're writing domain again, range.
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That's going to be our 2, 4, 8 and 4.
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Which we don't need to replace right again because it's already in there.
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So let's have 2, 4, 8.
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Now you're going to determine if it is a function.
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If you guys remember if it is a function, it's always a function.
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If you have every element in your domain, go ahead and map to exactly one element in
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your range.
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So negative 2 goes to 2, 2 goes to 4, 3 goes to 8 and 4 goes to 8.
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So therefore each element are domain maps to exactly one element into the range.
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So therefore this is a function.
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For example, if I added a point, if I added any one of these domain values, and let's
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say map to a different number, now this would not be a function.
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So you can see this right here.
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Now this is not going to be a function.
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So when you have this, you just need to make sure they map everything in domain and maps
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to everything in the range.
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And the next set is now what you look at is it going to be on to or one to one.
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First thing, on to, what that means is everything in the range has a map to the domain.
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So we look at there, and when you have quarter points, it's pretty easy to see if it's on
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to or not.
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And we notice that every element in our range maps to something in the domain.
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So therefore it is on to.
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On one to one, we look at this, everything in the one to one means everything in the domain
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has to uniquely go to something in the range.
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And what we'll notice is we both have a four here.
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We say two goes to four and four goes to four.
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So therefore four in a range is not uniquely mapped.
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So therefore this is not on to one.
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And that's how you determine if a set up points is a function and what type of relation
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it is.
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And what we'll notice is that every element in the domain is a function and what type of relation
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it is, every element in the domain is a function and what type of relation it is.
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So therefore this is not on to one.