Difference between revisions of "Vertical line test"
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| + | The '''vertical line test''' is a way of determining if a plotted [[graph]] is a [[function]]. | ||
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The vertical line test states that: | The vertical line test states that: | ||
| − | A relation is a [[function]] [[iff]] no vertical line intersects the graph in more than one point. | + | A [[relation]] is a [[function]] [[iff]] no vertical [[line]] intersects the graph in more than one point. |
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| + | This is because a function cannot have more than one output for one input. | ||
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| − | For example, <math>y=x^2</math> is a function because any vertical line intersects it in, at most, one point, while <math>x^2+y^2=1</math> is not a function (try x=0). | + | For example, <math>y=x^2</math> is a function because any vertical line intersects it in, at most, one point, while <math>x^2+y^2=1</math> is not a function (try the line <math>x=0</math>). |
Revision as of 10:43, 2 August 2006
The vertical line test is a way of determining if a plotted graph is a function.
The vertical line test states that:
A relation is a function iff no vertical line intersects the graph in more than one point.
This is because a function cannot have more than one output for one input.
For example, 
is a function because any vertical line intersects it in, at most, one point, while 
is not a function (try the line 
).
