Date:
Lesson Plan in: General Mathematics
I. CONTENT/ TOPIC : Functions and Relations
APPRECIATION
II. OBJECTIVES: .
a. The learner is able to distinguish functions and relations.
b. The learner is able to familiarize on different ways of representing a function.
c. The learner is able to appreciate the importance of functions in real-life situation.
III. REFERENCE : Exploring Mathematics (Intermediate Algebra ); Orlando A. Oronce,
Mendoza; pg.252-255
IV. Teaching Procedures/ Strategies :
a. Daily Routine
b. Simple Recall/ Review:
c. Motivation:
d. Development of the Lesson:
a. ACTIVITY: Concept Note #1
RELATIONS - any set of ordered pairs. The set of all the first coordinates is called the domain of
the relation. The set of all second coordinates is called the range.
Example 1: {(1,3), (1,2), (0,8), (9,3)}
Solution: This set of ordered pair is an example of relation, wherein the domain is {1, 0, 9} and the
range is {3, 2, 8}.
Example 2: {(1,4), (2,5), (3,6)}
Solution: This set of ordered pair is an example of relation, wherein the domain is {1, 2, 3} and the
range is {4, 5, 6}.
Example 3: {1, 3, 5, 7}
Solution: This set is not an example of relation, because this it is not a set of ordered pairs.
Example 4: {{2,3}, {2,5}}
Solution: This set is not an example of relation, but just a set of pairs of set.
FUNCTIONS- a relation in which for every first element x, there corresponds a unique second
element y.
A function can be denoted by y =f(x) , which reads “f of x” or “the value of the function at x” .
Note: Every function is a relation, but some relations are not functions.
A function can be represent in five different ways.
1.Function in ordered pair.
f(x) = {(1,6), (2,7), (3,8), (4,9), (5,10)}
2.Function in tabular form
X 1 2 3 4 5
y 6 7 8 9 10
3. Function in set notation / open sentence
f(x) = {(x,y) I y = x + 5} and x = {1,2,3,4,5}
In open sentence: y = x+5 such that x = 1,2,3,4,5
4. Arrow diagram / mapping
X Y
1 6
2 7
3 8
4 9
5 10
