<< Chapter < Page Chapter >> Page >

The number 50 is between what two whole numbers?

Since 7 2 = 49 , 49 = 7.

Since 8 2 = 64 , 64 = 8. Thus,

7 < 50 < 8

Thus, 50 is a number between 7 and 8.

A number line with arrows on each end, labeled at zero, seven and eight. Seven is also labeled as square root of forty-nine and eight is labeled as square root of sixty-four. There is a closed circle at square root of fifty and it is labeled as square root of fifty.

Got questions? Get instant answers now!

Practice set b

Write the principal and secondary square roots of each number.

100

100 = 10 and 100 = 10

Got questions? Get instant answers now!

121

121 = 11 and 121 = 11

Got questions? Get instant answers now!

Use a calculator to obtain a decimal approximation for the two square roots of 35. Round to two decimal places.

5.92  and  5.92

Got questions? Get instant answers now!

Meaningful expressions

Since we know that the square of any real number is a positive number or zero, we can see that expressions such as 16 do not describe real numbers. There is no real number that can be squared that will produce −16. For x to be a real number, we must have x 0. In our study of algebra, we will assume that all variables and all expressions in radicands represent nonnegative numbers (numbers greater than or equal to zero).

Sample set c

Write the proper restrictions that must be placed on the variable so that each expression represents a real number.

For x 3 to be a real number, we must have

x 3 0 or x 3

Got questions? Get instant answers now!

For 2 m + 7 to be a real number, we must have

2 m + 7 0 or 2 m 7 or m 7 2

Got questions? Get instant answers now!

Practice set c

Write the proper restrictions that must be placed on the variable so that each expression represents a real number.

Simplifying square roots

When variables occur in the radicand, we can often simplify the expression by removing the radical sign. We can do so by keeping in mind that the radicand is the square of some other expression. We can simplify a radical by seeking an expression whose square is the radicand. The following observations will help us find the square root of a variable quantity.

Since ( x 3 ) 2 = x 3 · 2 = x 6 , x 3 is a square root of x 6 . Also
Six divided by two is equal to three. There is an arrow pointing  towards six that is labeled as

Got questions? Get instant answers now!

Since ( x 4 ) 2 = x 4 · 2 = x 8 , x 4 is a square root of x 8 . Also

Eight divided by two is equal to four. There is an arrow pointing  towards eight that is labeled as

Got questions? Get instant answers now!

Since ( x 6 ) 2 = x 6 · 2 = x 12 , x 6 is a square root of x 12 . Also

Twelve divided by two is equal to six. There is an arrow pointing  towards twelve that is labeled as

Got questions? Get instant answers now!

These examples suggest the following rule:

If a variable has an even exponent, its square root can be found by dividing that exponent by 2.

The examples of Sample Set B illustrate the use of this rule.

Sample set d

Simplify each expression by removing the radical sign. Assume each variable is nonnegative .

a 2 . We seek an expression whose square is  a 2 .  Since ( a ) 2 = a 2 , a 2 = a Notice that  2 ÷ 2 = 1.

Got questions? Get instant answers now!

y 8 . We seek an expression whose square is  y 8 .  Since ( y 4 ) 2 = y 8 , y 8 = y 4 Notice that  8 ÷ 2 = 4.

Got questions? Get instant answers now!

25 m 2 n 6 . We seek an expression whose square is  25 m 2 n 6 .  Since ( 5 m n 3 ) 2 = 25 m 2 n 6 , 25 m 2 n 6 = 5 m n 3 Notice that  2 ÷ 2 = 1  and  6 ÷ 2 = 3.

Got questions? Get instant answers now!

121 a 10 ( b 1 ) 4 . We seek an expression whose square is  121 a 10 ( b 1 ) 4 . Since [ 11 a 5 ( b 1 ) 2 ] 2 = 121 a 10 ( b 1 ) 4 , 121 a 10 ( b 1 ) 4 = 11 a 5 ( b 1 ) 2 Then, 121 a 10 ( b 1 ) 4 = 11 a 5 ( b 1 ) 2 Notice that  10 ÷ 2 = 5  and  4 ÷ 2 = 2.

Got questions? Get instant answers now!

Practice set d

Simplify each expression by removing the radical sign. Assume each variable is nonnegative.

100 x 8 y 12 z 2

10 x 4 y 6 z

Got questions? Get instant answers now!

36 ( a + 5 ) 4

6 ( a + 5 ) 2

Got questions? Get instant answers now!

225 w 4 ( z 2 1 ) 2

15 w 2 ( z 2 1 )

Got questions? Get instant answers now!

0.25 y 6 z 14

0.5 y 3 z 7

Got questions? Get instant answers now!

x 2 n , where n is a natural number.

x n

Got questions? Get instant answers now!

x 4 n , where n is a natural number.

x 2 n

Got questions? Get instant answers now!

Exercises

How many square roots does every positive real number have?

two

Got questions? Get instant answers now!

The symbol represents which square root of a number?

Got questions? Get instant answers now!

The symbol – represents which square root of a number?

secondary

Got questions? Get instant answers now!

For the following problems, find the two square roots of the given number.

1 16

1 4 and 1 4

Got questions? Get instant answers now!

25 36

5 6  and  5 6

Got questions? Get instant answers now!

0.04

0.2 and 0.2

Got questions? Get instant answers now!

1.21

1.1 and 1.1

Got questions? Get instant answers now!

For the following problems, evaluate each expression. If the expression does not represent a real number, write "not a real number."

225

not a real number

Got questions? Get instant answers now!

1

not a real number

Got questions? Get instant answers now!

For the following problems, write the proper restrictions that must be placed on the variable so that the expression represents a real number.

2 x 8

x 4

Got questions? Get instant answers now!

For the following problems, simplify each expression by removing the radical sign.

36 x 22 y 44

6 x 11 y 22

Got questions? Get instant answers now!

169 w 4 z 6 ( m 1 ) 2

Got questions? Get instant answers now!

25 x 12 ( y 1 ) 4

5 x 6 ( y 1 ) 2

Got questions? Get instant answers now!

9 m 6 n 4 ( m + n ) 18

3 m 3 n 2 ( m + n ) 9

Got questions? Get instant answers now!

( f 2 ) 2 ( g + 6 ) 4

( f 2 ) ( g + 6 ) 4

Got questions? Get instant answers now!

( 2 c 3 ) 6 + ( 5 c + 1 ) 2

Got questions? Get instant answers now!

64 r 4 s 22

8 r 2 s 11

Got questions? Get instant answers now!

121 a 6 ( a 4 ) 8

Got questions? Get instant answers now!

[ ( w + 6 ) 2 ]

w + 6

Got questions? Get instant answers now!

[ 4 a 2 b 2 ( c 2 + 8 ) 2 ]

Got questions? Get instant answers now!

1.21 h 4 k 4

1.1 h 2 k 2

Got questions? Get instant answers now!

169 a 2 b 4 c 6 196 x 4 y 6 z 8

13 a b 2 c 3 14 x 2 y 3 z 4

Got questions? Get instant answers now!

[ 81 y 4 ( z 1 ) 2 225 x 8 z 4 w 6 ]

Got questions? Get instant answers now!

Exercised for review

( [link] ) Find the quotient. x 2 1 4 x 2 1 ÷ x 1 2 x + 1 .

x + 1 2 x 1

Got questions? Get instant answers now!

( [link] ) Find the sum. 1 x + 1 + 3 x + 1 + 2 x 2 1 .

Got questions? Get instant answers now!

( [link] ) Solve the equation, if possible: 1 x 2 = 3 x 2 x 2 3 x + 1 .

No solution ; x = 2 is excluded.

Got questions? Get instant answers now!

( [link] ) Perform the division: 15 x 3 5 x 2 + 10 x 5 x .

Got questions? Get instant answers now!

( [link] ) Perform the division: x 3 5 x 2 + 13 x 21 x 3 .

x 2 2 x + 7

Got questions? Get instant answers now!

Questions & Answers

Discuss the differences between taste and flavor, including how other sensory inputs contribute to our  perception of flavor.
John Reply
taste refers to your understanding of the flavor . while flavor one The other hand is refers to sort of just a blend things.
Faith
While taste primarily relies on our taste buds, flavor involves a complex interplay between taste and aroma
Kamara
which drugs can we use for ulcers
Ummi Reply
omeprazole
Kamara
what
Renee
what is this
Renee
is a drug
Kamara
of anti-ulcer
Kamara
Omeprazole Cimetidine / Tagament For the complicated once ulcer - kit
Patrick
what is the function of lymphatic system
Nency Reply
Not really sure
Eli
to drain extracellular fluid all over the body.
asegid
The lymphatic system plays several crucial roles in the human body, functioning as a key component of the immune system and contributing to the maintenance of fluid balance. Its main functions include: 1. Immune Response: The lymphatic system produces and transports lymphocytes, which are a type of
asegid
to transport fluids fats proteins and lymphocytes to the blood stream as lymph
Adama
what is anatomy
Oyindarmola Reply
Anatomy is the identification and description of the structures of living things
Kamara
what's the difference between anatomy and physiology
Oyerinde Reply
Anatomy is the study of the structure of the body, while physiology is the study of the function of the body. Anatomy looks at the body's organs and systems, while physiology looks at how those organs and systems work together to keep the body functioning.
AI-Robot
what is enzymes all about?
Mohammed Reply
Enzymes are proteins that help speed up chemical reactions in our bodies. Enzymes are essential for digestion, liver function and much more. Too much or too little of a certain enzyme can cause health problems
Kamara
yes
Prince
how does the stomach protect itself from the damaging effects of HCl
Wulku Reply
little girl okay how does the stomach protect itself from the damaging effect of HCL
Wulku
it is because of the enzyme that the stomach produce that help the stomach from the damaging effect of HCL
Kamara
function of digestive system
Ali Reply
function of digestive
Ali
the diagram of the lungs
Adaeze Reply
what is the normal body temperature
Diya Reply
37 degrees selcius
Xolo
37°c
Stephanie
please why 37 degree selcius normal temperature
Mark
36.5
Simon
37°c
Iyogho
the normal temperature is 37°c or 98.6 °Fahrenheit is important for maintaining the homeostasis in the body the body regular this temperature through the process called thermoregulation which involves brain skin muscle and other organ working together to maintain stable internal temperature
Stephanie
37A c
Wulku
what is anaemia
Diya Reply
anaemia is the decrease in RBC count hemoglobin count and PVC count
Eniola
what is the pH of the vagina
Diya Reply
how does Lysin attack pathogens
Diya
acid
Mary
I information on anatomy position and digestive system and there enzyme
Elisha Reply
anatomy of the female external genitalia
Muhammad Reply
Organ Systems Of The Human Body (Continued) Organ Systems Of The Human Body (Continued)
Theophilus Reply
what's lochia albra
Kizito
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, Elementary algebra. OpenStax CNX. May 08, 2009 Download for free at http://cnx.org/content/col10614/1.3
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Elementary algebra' conversation and receive update notifications?

Ask