THE REAL NUMBER SYSTEM
Natural Numbers: N = { 1, 2, 3, …}
Whole Numbers: W = { 0, 1, 2 , 3, ...}
Integers: I = {….. -3, -2, -1, 0, 1, 2, 3, ...}
Rational Numbers:
Irrational Numbers: Q = {non-terminating, non-repeating
decimals} π, e ,√2 , √ 3 ...
Real Numbers: R = {all rational and irrational}
Imaginary Numbers: i = {square roots of negative numbers}
Complex Numbers: C = { real and imaginary numbers}
Q =
a
b
| a,b ∈I,b ≠0





Natural
Numbers
Whole Numbers
Integers
Rational Numbers
IrrationalNumbers
Real Numbers
ImaginaryNumbers
Complex Numbers
1.1.4
Review
RADICALS
Index
Radicand
When the index of the radical is not shown then it
is understood to be an index of 2
Radical
=
EXAMPLE 1:
a) Give 4 examples of radicals
b) Use a different radicand and index for each
radical
c) Explain the meaning of the index of each radical
Evaluate each radical:
= 0.5
= 6
= 2
=
= 5
EXAMPLE 2:
Choose values of n and x so that is:
a) A whole number
b) A negative integer
c) A rational number
d) An approximate decimal
•
= 4
= 5/4
= 1.4141…
= -3
EXAMPLE 3:
4.2 Irrational Numbers
WORK WITH YOUR
PARTNER
1. How are radicals that are rational numbers
different from radicals that are not rational numbers?
Rational Numbers:
These are rational numbers: These are NOT rational numbers:
Q =
a
b
| a,b ∈I,b ≠0






2. Which of these radicals are rational numbers? Which ones are
not rational numbers?
How do you know?
WORK WITH YOUR
PARTNER
RATIONAL NUMBERS
a. Can be written in the form
b. Radicals that are square roots of perfect squares, cube roots of perfect
cubes etc..
c. They have decimal representation which terminate or repeats
Q =
a
b
| a,b ∈I,b ≠0





IRATIONAL NUMBERS
a. Can not be written in the form
b. They are non-repeating and non-terminating decimals
Q =
a
b
| a,b ∈I,b ≠0





EXAMPLE 1: Tell whether each number is rational or irrational. Explain how do you
know.
Rational, because 8/27 is a perfect cube.
Also, 2/3 or 0.666… is a repeating decimal.
Irrational, because 14 is not a perfect square.
Also, √14 is NOT a repeating decimal and DOES NOT
terminate
Rational, because 0.5 terminates.
Irrational, because π is not a repeating decimal and
does not terminates
POWER POINT PRACTICE PROBLEM
Tell whether each number is rational or irrational. Explain how do you know.
EXAMPLE 2:
Use a number line to order these numbers from least to greatest
Use Calculators!
-2 -1 0 1 2 3 4 5
EXAMPLE 2:
Use a number line to order these numbers from least to greatest
POWERPOINT PRACTICE PROBLEM
Use a number line to order these numbers from least to greatest
Index
Radicand
Review of Radicals
When the index of the radical is not shown then it is
understood to be an index of 2.
Radical
=
MULTIPLICATION PROPERTY of
RADICALS
Use Your Calculator to calculate:
What do you notice?
•
WE USE THIS PROPERTY TO:
Simplify square roots and cube roots
that are not perfect squares or perfect cubes,
but have factors that are perfect
MULTIPLICATION PROPERTY of
RADICALS
where n is a natural number, and a and b are real
numbers
Example 1:
•
Example 2:
•
Simplify each radical.
Write each radical as a product of prime factors,
then simplify.
Since √80 is a square root. Look for
factors that appear twice
Simplify each radical.
Write each radical as a product of prime factors,
then simplify.
Since 144∛ is a cube root. Look for
factors that appear three times
Simplify each radical.
Write each radical as a product of prime factors,
then simplify.
Since 162∜ is a fourth root. Look
for factors that appear four times
POWERPOINT PRACTICE PROBLEM
Simplify each radical.
Some numbers such as 200 have more than one
perfect square factor:
For example, the factors of 200 are:
1, 2 ,4, 5, 8, 10, 20, 25, 40, 50, 100, 200
Since 1, 4, 16, 25, 100, and 400 are perfect squares, we can
simplify √400 in several ways:
Writing Radicals in Simplest Form
Writing Radicals in Simplest Form
10√2 is in simplest form because the
radical contains no perfect square
factors other than 1
Mixed Radical:
the product of a number and a radical
Entire Radical:
the product of one and a radical
4 6
72
Writing Mixed Radicals as Entire Radicals
Any number can be written as the square root of
its square!
2 = 45 = 100 =
Any number can be also written as the cube root of
its cube, or the fourth root of its perfect fourth!
2 =
45 =
•
Writing Mixed Radicals as Entire Radicals
Write each mixed radical as an entire radical
POWERPOINT PRACTICE PROBLEM
Write each mixed radical as an entire radical

Presentation on the real number system

  • 1.
    THE REAL NUMBERSYSTEM Natural Numbers: N = { 1, 2, 3, …} Whole Numbers: W = { 0, 1, 2 , 3, ...} Integers: I = {….. -3, -2, -1, 0, 1, 2, 3, ...} Rational Numbers: Irrational Numbers: Q = {non-terminating, non-repeating decimals} π, e ,√2 , √ 3 ... Real Numbers: R = {all rational and irrational} Imaginary Numbers: i = {square roots of negative numbers} Complex Numbers: C = { real and imaginary numbers} Q = a b | a,b ∈I,b ≠0     
  • 2.
  • 3.
  • 4.
  • 5.
    Index Radicand When the indexof the radical is not shown then it is understood to be an index of 2 Radical =
  • 6.
    EXAMPLE 1: a) Give4 examples of radicals b) Use a different radicand and index for each radical c) Explain the meaning of the index of each radical
  • 7.
    Evaluate each radical: =0.5 = 6 = 2 = = 5 EXAMPLE 2:
  • 8.
    Choose values ofn and x so that is: a) A whole number b) A negative integer c) A rational number d) An approximate decimal • = 4 = 5/4 = 1.4141… = -3 EXAMPLE 3:
  • 9.
  • 10.
    WORK WITH YOUR PARTNER 1.How are radicals that are rational numbers different from radicals that are not rational numbers? Rational Numbers: These are rational numbers: These are NOT rational numbers: Q = a b | a,b ∈I,b ≠0      
  • 11.
    2. Which ofthese radicals are rational numbers? Which ones are not rational numbers? How do you know? WORK WITH YOUR PARTNER
  • 12.
    RATIONAL NUMBERS a. Canbe written in the form b. Radicals that are square roots of perfect squares, cube roots of perfect cubes etc.. c. They have decimal representation which terminate or repeats Q = a b | a,b ∈I,b ≠0     
  • 13.
    IRATIONAL NUMBERS a. Cannot be written in the form b. They are non-repeating and non-terminating decimals Q = a b | a,b ∈I,b ≠0     
  • 14.
    EXAMPLE 1: Tellwhether each number is rational or irrational. Explain how do you know. Rational, because 8/27 is a perfect cube. Also, 2/3 or 0.666… is a repeating decimal. Irrational, because 14 is not a perfect square. Also, √14 is NOT a repeating decimal and DOES NOT terminate Rational, because 0.5 terminates. Irrational, because π is not a repeating decimal and does not terminates
  • 15.
    POWER POINT PRACTICEPROBLEM Tell whether each number is rational or irrational. Explain how do you know.
  • 16.
    EXAMPLE 2: Use anumber line to order these numbers from least to greatest Use Calculators!
  • 17.
    -2 -1 01 2 3 4 5 EXAMPLE 2: Use a number line to order these numbers from least to greatest
  • 18.
    POWERPOINT PRACTICE PROBLEM Usea number line to order these numbers from least to greatest
  • 19.
    Index Radicand Review of Radicals Whenthe index of the radical is not shown then it is understood to be an index of 2. Radical =
  • 20.
    MULTIPLICATION PROPERTY of RADICALS UseYour Calculator to calculate: What do you notice?
  • 21.
    • WE USE THISPROPERTY TO: Simplify square roots and cube roots that are not perfect squares or perfect cubes, but have factors that are perfect MULTIPLICATION PROPERTY of RADICALS where n is a natural number, and a and b are real numbers
  • 22.
  • 23.
  • 24.
    Simplify each radical. Writeeach radical as a product of prime factors, then simplify. Since √80 is a square root. Look for factors that appear twice
  • 25.
    Simplify each radical. Writeeach radical as a product of prime factors, then simplify. Since 144∛ is a cube root. Look for factors that appear three times
  • 26.
    Simplify each radical. Writeeach radical as a product of prime factors, then simplify. Since 162∜ is a fourth root. Look for factors that appear four times
  • 27.
  • 28.
    Some numbers suchas 200 have more than one perfect square factor: For example, the factors of 200 are: 1, 2 ,4, 5, 8, 10, 20, 25, 40, 50, 100, 200 Since 1, 4, 16, 25, 100, and 400 are perfect squares, we can simplify √400 in several ways: Writing Radicals in Simplest Form
  • 29.
    Writing Radicals inSimplest Form 10√2 is in simplest form because the radical contains no perfect square factors other than 1
  • 30.
    Mixed Radical: the productof a number and a radical Entire Radical: the product of one and a radical 4 6 72
  • 31.
    Writing Mixed Radicalsas Entire Radicals Any number can be written as the square root of its square! 2 = 45 = 100 = Any number can be also written as the cube root of its cube, or the fourth root of its perfect fourth! 2 = 45 =
  • 32.
    • Writing Mixed Radicalsas Entire Radicals
  • 33.
    Write each mixedradical as an entire radical
  • 34.
    POWERPOINT PRACTICE PROBLEM Writeeach mixed radical as an entire radical