<< Chapter < Page Chapter >> Page >

Access these online resources for additional instruction and practice with absolute value.

Key concepts

  • Applied problems, such as ranges of possible values, can also be solved using the absolute value function. See [link] .
  • The graph of the absolute value function resembles a letter V. It has a corner point at which the graph changes direction. See [link] .
  • In an absolute value equation, an unknown variable is the input of an absolute value function.
  • If the absolute value of an expression is set equal to a positive number, expect two solutions for the unknown variable. See [link] .

Section exercises

Verbal

How do you solve an absolute value equation?

Isolate the absolute value term so that the equation is of the form | A | = B . Form one equation by setting the expression inside the absolute value symbol, A , equal to the expression on the other side of the equation, B . Form a second equation by setting A equal to the opposite of the expression on the other side of the equation, B . Solve each equation for the variable.

Got questions? Get instant answers now!

How can you tell whether an absolute value function has two x -intercepts without graphing the function?

Got questions? Get instant answers now!

When solving an absolute value function, the isolated absolute value term is equal to a negative number. What does that tell you about the graph of the absolute value function?

The graph of the absolute value function does not cross the x -axis, so the graph is either completely above or completely below the x -axis.

Got questions? Get instant answers now!

How can you use the graph of an absolute value function to determine the x -values for which the function values are negative?

Got questions? Get instant answers now!

Algebraic

Describe all numbers x that are at a distance of 4 from the number 8. Express this set of numbers using absolute value notation.

Got questions? Get instant answers now!

Describe all numbers x that are at a distance of 1 2 from the number −4. Express this set of numbers using absolute value notation.

| x + 4 | = 1 2

Got questions? Get instant answers now!

Describe the situation in which the distance that point x is from 10 is at least 15 units. Express this set of numbers using absolute value notation.

Got questions? Get instant answers now!

Find all function values f ( x ) such that the distance from f ( x ) to the value 8 is less than 0.03 units. Express this set of numbers using absolute value notation.

| f ( x ) 8 | < 0.03

Got questions? Get instant answers now!

For the following exercises, find the x - and y -intercepts of the graphs of each function.

f ( x ) = 4 | x 3 | + 4

Got questions? Get instant answers now!

f ( x ) = 3 | x 2 | 1

( 0 , 7 ) ; no x -intercepts

Got questions? Get instant answers now!

f ( x ) = 2 | x + 1 | + 6

Got questions? Get instant answers now!

f ( x ) = 5 | x + 2 | + 15

( 0 , 5 ) , ( 1 , 0 ) , ( 5 , 0 )

Got questions? Get instant answers now!

f ( x ) = 2 | x 1 | 6

( 0 , 4 ) , ( 4 , 0 ) , ( 2 , 0 )

Got questions? Get instant answers now!

f ( x ) = | 2 x + 1 | 13

( 0 , 12 ) , ( 6 , 0 ) , ( 7 , 0 )

Got questions? Get instant answers now!

f ( x ) = | x 9 | + 16

( 0 , 7 ) , ( 25 , 0 ) , ( 7 , 0 )

Got questions? Get instant answers now!

Graphical

For the following exercises, graph the absolute value function. Plot at least five points by hand for each graph.

For the following exercises, graph the given functions by hand.

y = | x 3 | 2

Graph of an absolute function.
Got questions? Get instant answers now!

f ( x ) = | x 1 | 2

Got questions? Get instant answers now!

f ( x ) = | x + 3 | + 4

Graph of an absolute function.
Got questions? Get instant answers now!

f ( x ) = 2 | x + 3 | + 1

Got questions? Get instant answers now!

f ( x ) = 3 | x 2 | + 3

Graph of an absolute function.
Got questions? Get instant answers now!

f ( x ) = | 2 x 4 | 3

Got questions? Get instant answers now!

f ( x ) = | 3 x + 9 | + 2

Graph of an absolute function.
Got questions? Get instant answers now!

f ( x ) = | x 1 | 3

Got questions? Get instant answers now!

f ( x ) = | x + 4 | 3

Graph of an absolute function.
Got questions? Get instant answers now!

f ( x ) = 1 2 | x + 4 | 3

Got questions? Get instant answers now!

Technology

Use a graphing utility to graph f ( x ) = 10 | x 2 | on the viewing window [ 0 , 4 ] . Identify the corresponding range. Show the graph.

range: [ 0 , 20 ]

Graph of an absolute function.
Got questions? Get instant answers now!

Use a graphing utility to graph f ( x ) = 100 | x | + 100 on the viewing window [ 5 , 5 ] . Identify the corresponding range. Show the graph.

Got questions? Get instant answers now!

For the following exercises, graph each function using a graphing utility. Specify the viewing window.

f ( x ) = 0.1 | 0.1 ( 0.2 x ) | + 0.3

x - intercepts:

Graph of an absolute function.
Got questions? Get instant answers now!

f ( x ) = 4 × 10 9 | x ( 5 × 10 9 ) | + 2 × 10 9

Got questions? Get instant answers now!

Extensions

For the following exercises, solve the inequality.

If possible, find all values of a such that there are no x - intercepts for f ( x ) = 2 | x + 1 | + a .

Got questions? Get instant answers now!

If possible, find all values of a such that there are no y -intercepts for f ( x ) = 2 | x + 1 | + a .

There is no solution for a that will keep the function from having a y -intercept. The absolute value function always crosses the y -intercept when x = 0.

Got questions? Get instant answers now!

Real-world applications

Cities A and B are on the same east-west line. Assume that city A is located at the origin. If the distance from city A to city B is at least 100 miles and x represents the distance from city B to city A, express this using absolute value notation.

Got questions? Get instant answers now!

The true proportion p of people who give a favorable rating to Congress is 8% with a margin of error of 1.5%. Describe this statement using an absolute value equation.

| p 0.08 | 0.015

Got questions? Get instant answers now!

Students who score within 18 points of the number 82 will pass a particular test. Write this statement using absolute value notation and use the variable x for the score.

Got questions? Get instant answers now!

A machinist must produce a bearing that is within 0.01 inches of the correct diameter of 5.0 inches. Using x as the diameter of the bearing, write this statement using absolute value notation.

| x 5.0 | 0.01

Got questions? Get instant answers now!

The tolerance for a ball bearing is 0.01. If the true diameter of the bearing is to be 2.0 inches and the measured value of the diameter is x inches, express the tolerance using absolute value notation.

Got questions? Get instant answers now!

Questions & Answers

how to create a software using Android phone
Wiseman Reply
how
basra
what is the difference between C and C++.
Yan Reply
what is software
Sami Reply
software is a instructions like programs
Shambhu
what is the difference between C and C++.
Yan
yes, how?
Hayder
what is software engineering
Ahmad
software engineering is a the branch of computer science deals with the design,development, testing and maintenance of software applications.
Hayder
who is best bw software engineering and cyber security
Ahmad
Both software engineering and cybersecurity offer exciting career prospects, but your choice ultimately depends on your interests and skills. If you enjoy problem-solving, programming, and designing software syste
Hayder
what's software processes
Ntege Reply
I haven't started reading yet. by device (hardware) or for improving design Lol? Here. Requirement, Design, Implementation, Verification, Maintenance.
Vernon
I can give you a more valid answer by 5:00 By the way gm.
Vernon
it is all about designing,developing, testing, implementing and maintaining of software systems.
Ehenew
hello assalamualaikum
Sami
My name M Sami I m 2nd year student
Sami
what is the specific IDE for flutter programs?
Mwami Reply
jegudgdtgd my Name my Name is M and I have been talking about iey my papa john's university of washington post I tagged I will be in
Mwaqas Reply
yes
usman
how disign photo
atul Reply
hlo
Navya
hi
Michael
yes
Subhan
Show the necessary steps with description in resource monitoring process (CPU,memory,disk and network)
samuel Reply
What is software engineering
Tafadzwa Reply
Software engineering is a branch of computer science directed to writing programs to develop Softwares that can drive or enable the functionality of some hardwares like phone , automobile and others
kelvin
if any requirement engineer is gathering requirements from client and after getting he/she Analyze them this process is called
Alqa Reply
The following text is encoded in base 64. Ik5ldmVyIHRydXN0IGEgY29tcHV0ZXIgeW91IGNhbid0IHRocm93IG91dCBhIHdpbmRvdyIgLSBTdGV2ZSBXb3puaWFr Decode it, and paste the decoded text here
Julian Reply
what to do you mean
Vincent
hello
ALI
how are you ?
ALI
What is the command to list the contents of a directory in Unix and Unix-like operating systems
George Reply
how can i make my own software free of cost
Faizan Reply
like how
usman
hi
Hayder
The name of the author of our software engineering book is Ian Sommerville.
Doha Reply
what is software
Sampson Reply
the set of intruction given to the computer to perform a task
Noor
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Algebra and trigonometry. OpenStax CNX. Nov 14, 2016 Download for free at https://legacy.cnx.org/content/col11758/1.6
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Algebra and trigonometry' conversation and receive update notifications?

Ask