This module will teach you how to deal with patterns, specifically, number patterns. These number patterns are called sequences.
As you go over the lessons and activities, you will be able to learn how to generate patterns, illustrate arithmetic sequence and to find its nth term.
Most Essential Learning Competencies
Generates patterns
Illustrates arithmetic sequence
Determines arithmetic means, nth term of an arithmetic sequence and sum of the terms of a given arithmetic sequence
Do not write anything on this module. Use your notebook and a sheet of paper for your answers to every activity. All answer sheets will be collected by your teacher.
What I Know
1. Read each item carefully
2. Choose the letter of the correct answer
3. Write it on a separate sheet of paper
Arithmetic sequence
A sequence where the difference between any two consecutive terms is constant
This module will help you understand more important concepts on patterns that you can apply in your daily life.
What's New
Learn how to generate patterns in numbers
Patterns can be seen in shapes and in nature. Patterns generated in the pictures and the number of seats in the auditorium are examples of sequences.
What is It
Complete the pattern generated from the activity
Finite sequence
A sequence with a last term
Infinite sequence
A sequence that continues indefinitely
Activity 2: Finite or Infinite?
Identify whether the sequence is finite or infinite
A sequence is said to be finite if its domain is the set {1, 2, 3,...,n} and is said to be infinite if its domain is the set of positive integers.
General term
The function that generates the terms of a sequence
Activity 3: Term after Term
1. Find the first five terms of sequences with given general terms
2. Find the 15th term of a sequence with a given general term
3. Find the 10th term of a given arithmetic sequence
2n + 1
General term of the sequence
Finding the first 5 terms of the sequence
1. For n=1, a1=2(1)+1=3
2. For n=2, a2=2(2)+1=5
3. For n=3, a3=2(3)+1=7
4. For n=4, a4=2(4)+1=9
5. For n=5, a5=2(5)+1=11
Suppose n=12, then, a12=2(12)+1=25
Generating number sequences is easy
Find the first five terms of the sequence whose general term is
an =3n
an =10-2n
The first five terms of the sequence an =3n are 3,9,27,81,243
The first five terms of the sequence an =10-2n are 8,6,4,2,0
The 15th term of the sequence an = n+1/n is 16/15
The 10th term of the sequence 1,5,9,13,... is 37
Generating a rule for a sequence from the first few terms is not always easy
Find a formula for the nth term of the sequence 2, 11, 26, 47, ...
an = 3n^2 - 1
Find the general term for the sequence 4, 5/8, 6/27, 7/64,...
an = (n+3)/n^3
Find the general term of the sequence whose first five terms are 1/2, 3/4, 5/6, 7/8, 9/10,...
an = (2n-1)/2n
Find the nth term of the sequence -2, 4, -8, 16, -32, 64...
an = -2^n
Finite sequences have a domain of {1, 2, 3, ..., n} where n is a natural number
Infinite sequences have a domain of the set of positive integers
Generating patterns is important in problem solving
Advantages of generating a rule in a sequence include being able to find any term in the sequence and understand the underlying structure
Situations where generating a rule can help solve problems
Predicting future values in a sequence
Optimizing a process with a pattern
Identifying trends in data
Sequence numbers
36
9, 89, 86, 83, 80
1.2, 1.8, 2.4
2/3, 1, 4/3, 5/3, 2
Activity 2: Arithmetic or Not?
1. Identify whether the sequence is arithmetic or not
2. If it is, find the common difference and the next three terms
To find the nth term of an arithmetic sequence, a formula would help
Arithmetic sequence
A sequence where every term after the first is obtained by adding a constant called the common difference
Finding the nth term of an arithmetic sequence
Use the formula: an = a1 + (n-1)d, where an is the nth term, a1 is the 1st term, and d is the common difference