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''' 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>).
  
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In other words, for every x value, there should only be one y value.
  
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>).
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{{stub}}
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[[Category:Algebra]]
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[[Category:Functions]]

Revision as of 13:02, 14 July 2021

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 $x=0$).

In other words, for every x value, there should only be one y value.

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