Piecewise
Function
Mr. Amer Ian D. Gagarin
— Prayer Leader
Objectives
01 Determines 02 Find
the domain and range
piecewise functions;
in piecewise functions;
03 Evaluates 04 Represents
real-life scenario
piecewise functions;
involving piecewise
and
functions.
01
Activity
Evaluating functions.
Plus 1
Mr. Casas St. Lisieux
Mr. Pulido Bl. Gerard
Mr. Lim St. Pio
02
Review
Evaluating functions.
Plus 2
Give me a video solution with full
narration to receive plus 2 in our
first quiz. Items 3 and 5 for boys,
and items 4 and 6 for girls.
Submission is until August 23 if
your schedule is MTh. August 24 if
TF schedule.
Solutions:
Substitute 3 to every x
in the equation
Solutions:
Substitute -5 to every x
in the equation
03
Introduction
What is piecewise looks like?
Piecewise
A piecewise function is a function that is defined by different
formulas or functions for each given interval. It’s also in the
name: piece. The function is defined by pieces of functions
for each part of the domain.
Piecewise
Piecewise
It looks like this:
Example:
● when x is less than 2, it gives x2,
● when x is exactly 2 it gives 6
● when x is more than 2 and less
than or equal to 6 it gives the
line 10-x
(a solid dot means "including",
an open dot means "not including")
Piecewise
And this is how we write it: It looks like this:
(a solid dot means "including",
an open dot means "not including")
Domain???
And this is how we write it: It looks like this:
The Domain (all the values of x that can go into the function)
(using Interval Notation)
(using Set Builder Notation)
Range???
And this is how we write it: It looks like this:
The Range (all the values of y that can go into the function)
(using Interval Notation)
(using Set Builder Notation)
Table of Values/Testing
And this is how we write it: And here are some example values:
X Y
−4 16
−2 4
0 0
1 1
2 6
3 7
Another
X Y
−1 2
0 2
1 2
2 2
3 3
4 4
Real-life Problem
Doctor’s fee
Doctor’s rate in the Philippines
● Up to 30 minutes costs 500;
● Over 30 and up to 1 hour costs 800; and
● Over 1 hour costs 800 plus 15 per minute
above 1 hour.
Doctor’s rate
● Up to 30 minutes costs 500;
● Over 30 and up to 1 hour costs 800; and
● Over 1 hour costs 800 plus 15 per minute above 1 hour.
{
{
1. You visit for 29 minutes, what is the fee?
2. You visit for 31 minutes, what is the fee?
3. You visit for 1 hour and 58 minutes, what is the fee?
Answers:
{
1. 29 minutes for 500 pesos
2. 31 minutes for 800 pesos
3. 1 hour and 58 minutes for 1,670 pesos
04
More
Examples
05
Cli
ck
me
!
Step Function