Difference between revisions of "Vertical line test"

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The '''vertical line test''' is a way of determining if a plotted [[graph of a function | graph]] is a [[function]].
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The '''vertical line test''' is a way of determining whether or not a plotted [[graph of a function|graph]] is a [[function]].
  
The vertical line test states that:
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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 any one input.
  
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 the line <math>x=0</math>).
  
 
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>).
 
 
{{stub}}
 
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[[Category:Algorithms]]
 
[[Category:Algorithms]]
 
[[Category:Elementary algebra]]
 
[[Category:Elementary algebra]]
 
[[Category:Functions]]
 
[[Category:Functions]]

Revision as of 18:30, 25 April 2008

The vertical line test is a way of determining whether or not 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 any one input.

For example, $y=x^2$ is a function because any vertical line intersects it in, at most, one point, while $x^2+y^2=1$ is not a function (try the line $x=0$).

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