How do you decide whether the relation $abs(x)-y=5$ defines a function?

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Answer 1 · 2017-07-09T22:17:56

As $x$ is the independent variable and any 1 value of $x$ gives only 1 answer for $y$ this is a function

This is called a one-to-one mapping

Make $x$ the independent variable and $y$ the dependent (the answer)

Add $y$ to both sides

$|x|=5+y$

Subtract 5 from both sides

$y=|x|-5$

As $x$ is the independent variable and any 1 value of $x$ gives only 1 answer for $y$ this is a function

This is called a one-to-one mapping

Tony B

How do you decide whether the relation abs(x)-y=5abs(x)-y=5 defines a function?