Function Math Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

easy
Is the relation {(2,4),(3,6),(2,8)}\{(2, 4), (3, 6), (2, 8)\} a function? Explain.

Solution

  1. 1
    Check whether any input is repeated with different outputs. The input 22 maps to both 44 and 88.
  2. 2
    Since the input 22 has two different outputs, this relation is not a function.

Answer

Not a function.\text{Not a function.}
When an input value appears more than once with different outputs, the relation violates the definition of a function.

About Function

A function is a rule that assigns to each input in the domain exactly one output in the codomain — every input maps to precisely one output, never two.

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More Function Examples

Example 1 easy

Determine whether the relation [formula] is a function.

Example 2 medium

Does the equation [formula] define [formula] as a function of [formula]?

Example 4 hard

A graph passes through the points [formula], [formula], [formula], and [formula]. Does this graph re

Example 5 medium

Given [formula], find [formula] and determine if [formula] is a function.

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