What is a set?
What is well-defined set
= is a collection of objects
A set is well defined if given an object it can be categorically
identified to belong to collection or not
What are the things you can see
(tree, dog, cat people, table, laptop,) that can be seen and
satisfy the requirements of this selection
( heat ,oxygen) we cannot see and not satisfy the
rreuirment
The element of the set must be somehow related and well
defined
For example
1. Good teachers what if I asked you to make a decent
with pictures that can you make a set for this
2. Intelligent students
For example
Determine with explanation, whether the given collection is
weel define or not
1. Collection of big bags = is not well define bec it
depend on the observer
2. Collection leafy vegetables well define set
3. Collection of soft stuffed toys not well define we can
tell whether the stuffed toy is soft or not
4. Collection of yellow fruit well define bec we can tell
whether the fruit is yellow or not
Ex set of cellphone or set of metro manila cities
What is not well defined set
For example
Determine which element or member does not belong to the
collection
A collection is not well define if it uses subjective phrases; in
which to determine whether he object belongs to collection
or not depend to the opinion of the observer
1 ( , goat, carabao, cat, cow, fish)
2. (6, 8, 9, 10, 12)
3. ( Marikina, manila, pasig, pasay, bicol)
To make it simple here the definition of the set
Sett is a collection of well defined and objects
Let elaborate this idea by an activity
https://www.youtube.com/watch?v=3V7cfNbJAE8
https://www.youtube.com/watch?v=uPpyDY5ZLKY
https://www.youtube.com/watch?v=xOl-VaZUg5Y
https://www.youtube.com/watch?v=2E-lUPv6-Bo
https://www.youtube.com/watch?v=eze6aOHC2fk
https://www.youtube.com/watch?v=nQ56Lnxtlwg
https://www.youtube.com/watch?v=Koz2x4KDlK4
https://www.youtube.com/watch?v=kGyOrbbllEY
https://www.youtube.com/watch?v=6qTzP03waOA
a
Collection of positive
integers
Collection of math boos in
the library
Collections of animals
weighing at leat 300kg
Collection of names of the
students in a school
b
Collection of rich people
Collection of large animals
https://www.youtube.com/watch?v=nCtPJn4o87I
https://www.math-only-math.com/basic-concepts-ofsets.html
Collection of nice objects
https://www.youtube.com/watch?v=e7w5coC0FrM
Collection of bright objects
https://www.math-only-math.com/basic-concepts-ofsets.html
https://www.youtube.com/watch?v=uPpyDY5ZLKY
quiz
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
The set of month in a year . s
The set of even integers from o to 20. S
The best 3 songs of 2018 . not
The favorite hamburger restaurant in the Philippines
not
set of beautiful women . not
set of scary story in the world not
set of a popular person not
set of a positive person not
set of scary story in the world not
The collection of vowels in English alphabets
collection of “Red flowers”
A group of “Singers with ages between 18 years and
25 years”
The collection of past presidents of the Philippines
Set of days in a week
Set of 3 good movies not
Example of not well-defined set :
S is a set of scary story in the world
S is a not well-defined set because we do not know how to
define scary.
C is a set of beautiful women
C is a not well-defined set because we do not know how to
define beautiful.
X is a set of a popular person
X is a not well-defined set because no accurate assessment
of popular.
Y is a set of a great newspaper
Y is a not well-defined set because we do not know how to
classify newspapers by great or not it is.
A is a set of a positive person
A is a not well-defined set because no accurate assessment
of positive.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
The set of month in a year
set of beautiful women
The set of even integers from o to 20.
The best 3 songs of 2018 .
set of scary story in the world
set of a popular person
set of a positive person
set of scary story in the world
The collection of vowels in English alphabets
collection of “Red flowers”
The favorite hamburger restaurant in the
Philippines
A group of “Singers with ages between 18 years
and 25 years”
The collection of past presidents of the
Philippines
Set of days in a week
Set of 3 good movies