Functions - Smarties

Functions - Smarties

By - Lily, Ian, Alex, Lucas, Anika, and Cameron

Domain and Range​

Domain and Range are values of x and y. Domain is the X-coordinates and Range is Y-coordinates. For every domain there's one range.

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How to determine whether a relation is a function?

Say you have 3 X-values that are 1,2,3 and Y-values of 4,10,5 the relation is a function because the X-values are all different and the Y-values are not very important. Another is to say you have 3 X-values that are 2,4,5,2 and Y-values of 2,3,7,10 the relation is not a function because there are repeated X-values which does not work.

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Vertical line test 

You use the vertical line test to determine if a graph shows a function or not. If a vertical line intersects a line more than once then it is not a function.

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Ordered Pairs and tables

(1,2) (1,5) (3,4) (8,7)

There are two of the 

same x-values in the

ordered pairs.

Meaning it's not a function.

​(1,2) (3,6) (7,9) (8,5)

All the X-values are different meaning its a function.​

Substitution

When you have an equation like 4x+y=12 you would first need to make a table. You can make a table by substituting the x values: -1, 0, 1, 2

Once you have the y values by substituting x, you’ll have your four ordered pairs. You can determine if it is a function from there by using the other methods already taught.

Practice Questions

Is this a function? -3x+y=8

Is this a function? (8,9) (4,3) (10,9) (18,3)

​Is this a function? Is this a function?

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