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In the following table, is y a function

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of x. In order for y to be a function of x

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For any x that we input into our little function

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box. So let's say this is y as a function of x. It needs

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to spit out only one value of y

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If it spits multiple values of y, then it might be a relationship but it's not

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going to be a function. So this is a function. This is a

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function. If we have a situation where we input x

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into a box, it could be multiple possible y's

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then this is not a function

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So let's think about this table right over here. When x is equal to

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1 we get y is equal to 1, but when x is

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equal to 1 again all of a sudden y is equal to 2

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So here we have a situation where we input 1 into our

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little relationship box, and when we input 1 into our relationship

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box, we could get a 1 or we could get a

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2 for y. So this is definitely not a

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function. For any input into a function it has to map to exactly one

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output. Here it is mapping to two outputs, so this is not

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a function.