IXL - Identify functions (Algebra 2 practice)

Look at this table:

x	y
^–15	20
17	20
6	^–8

Is this relation a function?

yes

ref_doc_title.

Learn with an example

question

Look at this graph:

Is this relation a function?

yes

key idea

You can use the vertical line test on a graph to determine whether a relation is a function.

If it is impossible to draw a vertical line that intersects the graph more than once, then each x-value is paired with exactly one y-value. So, the relation is a function.

If it is possible to draw a vertical line that intersects the graph more than once, then there is an x-value that is paired with more than one y-value. So, the relation is not a function.

solution

Apply the vertical line test:

It is impossible to draw a vertical line that intersects the graph more than once, so the relation is a function.

Looking for more? Try these:

Lesson: Relations and functions

$Confetti$

Excellent!

Now entering the Challenge Zone—are you ready?

Questions
answeredQuestions

Time
elapsedTime

hr	min	sec
00	00	06

SmartScore
out of 100
IXL's SmartScore is a dynamic measure of progress towards mastery, rather than a percentage grade. It tracks your skill level as you tackle progressively more difficult questions. Consistently answer questions correctly to reach excellence (90), or conquer the Challenge Zone to achieve mastery (100)! Learn more

Teacher tools

Work it out

Not feeling ready yet? These can help:

A.1Domain and range

Lesson: Relations and functions

Excellent! You got that right!

Jumping to level 1 of 1

Excellent!