SEMI DETAILED LESSON PLAN
GRADE 11 – GENERAL MATHEMATICS
I.
OBJECTIVES: At the end of the lesson, the students are expected to:
1. define what is inverse function; and
2. find the inverse of the function
II.
SUBJECT MATTER: Inverse Function
a. Reference:
Oronce, O.(2016). General Mathematics. Rex Bookstore, Inc.
b. Materials: Powerpoint Presentation
c. Teaching Strategy: Lecture Method
III.
PROCEDURE
1. Prayer
2. Greetings
3. Checking of Attendance
4. Drill
 The teacher will have a game about guessing the rule given the constructed table of
values.
x
y
-2
-6
-1
-5
0
-4
1
-3
2
-2
x -2 -1 0 1 2
y 2 -4 -6 -4 2
5. Review
 The teacher ask the following questions to the students
 Between the two given functions, which function represents one- to-one
function?
 What is one-to-one function then?

IV.
To determine if the students understood the previous lesson, the teacher will show
sets of coordinates and functions and students will determine if it is one-to-one
function.
1. (2, 9), (4, 5), (11, 5)
3. F(x) = 2x
2.(1,1),(9,3),(14, 4),(4,2)
4. Y = x2 + 13
DEVELOPMENTAL ACTIVITIES
1. Motivation
 The teacher will present unarranged phrase to be arranged by the students.
EENMIRTED ETH EREVNIS FO A ENO-OT-ENO
NITOCNUF
2. Presentation
 The teacher restate the lesson and the lesson objectives.
Our topic for today is to determine the inverse of a one-to-on function and at the end
of the discussion, you are expected to define what inverse function is, and find the
inverse of the function.
3. Discussion
 The teacher will ask the students how they define the word “INVERSE” and relate it
in function.
x
y

-2
-6
-1
-5
0
-4
1
-3
2
-2
x
y
-6
-2
-5
-1
-4
0
-3
1
-2
2
Base on the illustration what do you mean by inverse?
A relation reversing the process performed by any function f(x) is called inverse of
f(x). This means that the every element of the range corresponds to exactly one
element of the domain.

Why is it that one-to-one function? Why not all function?
One-to-one
function but not one-to-one:
x
y
-2
-6
-1
-5
0
-4
1
-3
2
-2
x
y
-2
4
-1
1
0
0
1
1
2
4
x
y
-6
-2
-5
-1
-4
0
-3
1
-2
2
x
y
4
-2
-5
-1
-4
0
-3
1
-2
2
A function has an inverse if and only of it is one-to-one.
EXAMPLES:
1. Find the inverse of a function described by the set of ordered pairs {(0, -2), (1, 0), (2,
2), (3, 4)}.
Answer: {(-2, 0), (0, 1), (2, 2), (4, 3)}.
2. Find the inverse of a function f(x) = 3x + 1.
f(x) = 3x + 1
y = 3x + 1
x = 3y + 1
𝑥−1
y= 3
𝑥−1
f -1(x)= 3
3. Find the inverse of the function f(x) = 5x + 6.
f(x) = 5x + 6
y = 5x + 6
x = 5y + 6
𝑥−6
y= 5
𝑥−6
f -1(x)= 5

Based on the given examples how do we find the inverse of the function?
To find the inverse function, these are the steps:
1.
2.
3.
4.
V.
Replace f(x) with y.
Interchange x and y
Solve for the new y in the equation
Replace the new y with f -1(x).
GENERALIZATION
 The following question will be asked to students
 What do you mean by inverse function?
 Are all functions have their inverse function?
 How to find the inverse of one-to-one function?
 What are the properties of inverse function?
VI.
EVALUATION
Directions: Answer the given problem.
1. Which among the following functions has an inverse?
a. f(x) = x3 – 5
b. g(x) = 3x -8
c. h(x) = x2
d. k(x) = lxl
e. l(x) = x2 -6x
2. Find the inverse of the f(x) = -x3 + 5
3. Find f(x) if f -1 (x) = x -2.
VII.
ASSIGNMENT
Prove that the inverse of a linear function is also a linear and the two slopes are reciprocal
of each other.
PREPARED BY:
REY C. SALARDA
Subject Teacher
CHECKED BY:
ROSALINA I. TACAN, HT-III
Asst. to the Principal for Academics, SHS