# 1.01 Review: Relations and functions

## Interactive practice questions

Express the relation $\left\{\left(2,2\right),\left(4,4\right),\left(6,3\right),\left(7,5\right)\right\}${(2,2),(4,4),(6,3),(7,5)} in the table below.

$x$x $y$y
$2$2 $\editable{}$
$4$4 $\editable{}$
$6$6 $\editable{}$
$7$7 $\editable{}$
Easy
Less than a minute
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True or False?

When working with a function, substituting a certain value of $x$x into the formula gives only one value of $y$y for that value of $x$x.

Consider the following statement:

All relations are functions.

True or false?

A relation always passes the vertical line test.