3. Sequences
Definitions:
09/06/2023
Sequence A sequence is a list of numbers in a special order.
Term Each number in a sequence is called a term.
Term to Term Rule Defines the value of each term in a sequence
Linear Sequence
A sequence that increases/decreases by the same
amount each time.
4. Sequences 1
Discussion 1:
Sam is a biologist for a seed. She records the growth of Brand X bean
plants over six days.
Sam notices that Brand X bean plants grow to a number pattern.
She decides to create a table to show this.
09/06/2023
Day 1 Day 2 Day 3 Day 4 Day 5
5. plants over six days.
Sam notices that Brand X bean plants grow to a number pattern.
She decides to create a table to show this.
The number pattern can be written as a sequence.
Day 1 Day 2 Day 3 Day 4 Day 5
Day 1 2 3 4 5
Number of leaves 2 4 6 8 10
6. Sequences 1
Discussion 2:
Look at this Spanish tile pattern and determine the sequence that was
used and find the next five terms.
The sequence for the pattern is 1, 5, 9, 13β¦
The term-to-term rule:
The next five terms are
09/06/2023
1 tile 5 tiles 9 tiles 13 tiles
17 21 25 29 33
Starts at 1 and add 4
7. Sequences 1
Discussion 3:
a) Write a sequence for the number of dots in each term as the
sequence progresses,
b) What is the term-to-term rule for the sequence?
c) Use the rule to extend the sequence to the 5th term
09/06/2023
1, 3, 5, ........
Starts at 1, and add 2
1 3 5 7 9
8. Sequences
Examples:
09/06/2023
eg1 Find the T2T rule and the next
two terms of the sequence.
3, 5, 7, 9 β¦
eg2 Find the T2T rule and the next
two terms of the sequence.
2, 8, 32, 128 β¦
Try Find the T2T rule and the next two
terms of the sequence.
25, 28, 31, 34 β¦
Try Find the T2T rule and the next two
terms of the sequence.
2, 6, 18, 54 β¦
T2T Rule: +2
Next 2 terms: 11, 13 β¦
T2T Rule: +3
Next 2 terms: 37, 40 β¦
T2T Rule: Γ 4
Next 2 terms: 512, 2048 β¦
T2T Rule: +3
Next 2 terms: 162, 486 β¦
9. Task 1:
1 Find the term to term rule and the next two terms in the sequence.
a 4, 6, 8, 10 β¦ b 5, 7, 9, 11 β¦ c 2, 9, 1, 1, 7 β¦
There are non examples
d 2, 4, 8, 16 β¦ e 7, 10, 13, 16 β¦ f 21, 19, 17, 15 β¦
g 1024, 256, 64, 16 β¦ h 0, 6, 12, 18 β¦ i β9, β3, 3, 9 β¦
j 1, 4, 9, 16, 25 β¦ k β3, 3, 13, 27 β¦ l 0, 6, 16, 30 β¦
m 2π₯, 4π₯, 6π₯, 8π₯ β¦ n 2π₯, 4π₯, 8π₯, 16π₯ β¦ o 2π₯ + 2, 3π₯ + 5, 4π₯ + 8
+π
12, 14 β¦
+π
13, 15 β¦
π΅ππ β π¬ππππππ
Γ π
32, 64 β¦
+π
19, 22 β¦
βπ
13, 11 β¦
Γ· π
4, 1 β¦
+π
24, 30 β¦
+π
15, 21 β¦
+π, +π, +π β¦
36, 49 β¦
+π, +ππ, +ππ β¦
45, 67 β¦
+π, +ππ, +ππ β¦
48, 70 β¦
+ππ
10π₯, 12π₯ β¦
Γ π
32π₯, 64π₯ β¦
+(π + π)
5π₯ + 11, 6π₯ + 14 β¦
2 Find the term to term rule and the draw the next picture.
+3 π ππ’ππππ
3 Is 318 a term in the sequence 1, 9, 17, 25β¦?
No the terms are all odd numbers.
10. Sequences
Examples:
09/06/2023
eg3 Use the T2T rule to find the
first 5 terms in the sequence.
Starts at 6, +π
Try Use the T2T rule to find the
first 5 terms in the sequence.
Starts at 6, βπ
6 9 12 15 18 6 3 0 -3 -6
11. Task 2:
1 Use the T2T rule to find the first 5 terms in the sequence.
a ππ‘πππ‘: π π π’ππ: +π b ππ‘πππ‘: π π π’ππ: +π c ππ‘πππ‘: π π π’ππ: +π
4, 7, 10, 13, 16 5, 8, 11, 14, 17 5, 9, 13, 17, 21
d ππ‘πππ‘: π π π’ππ: Γ π e ππ‘πππ‘: π π π’ππ: βπ f ππ‘πππ‘: ππ π π’ππ: βπ
1, 3, 9, 27, 81 5, 1, β3, β7, β11 10, 5, 0, β5, β10
g ππ‘πππ‘: π π π’ππ: Γ π πππ + π
1, 3, 7, 15, 31, 63
h ππ‘πππ‘: ππ π π’ππ: +π πππ Γ· π
33, 17, 9, 5, 3
i ππ‘πππ‘: π + π π π’ππ: +(ππ + π)
π₯ + 5, 3π₯ + 8, 5π₯ + 11, 7π₯ + 14, 9π₯ + 17
j ππ‘πππ‘: ππ π π’ππ: Γ (ππ)
2π₯, 4π₯2
, 8π₯3
, 16π₯4
, 32π₯5
2
The rule is to add four.
Explain why she has not described
the rule for a sequence.
The first term of her sequence is a
factor of 18. Come up with 3
different sequences.
Sofia is writing a sequence. a
b
16. Sequences 2
Discussion:
09/06/2023
Take a look at the sequence
7, 11, 15, 19 β¦
Find the term to term rule. +4
Find the next two terms. 23 27
Find the 10th term. 31 35 39 43
Find the 80th term.
It will take a long time to find this
term using the term to term rule.
We can use the position to term rule.
4π + 3
= 4 80 + 3
= 320 + 3
= 323
17. Sequences 2
Definitions:
09/06/2023
Position to Term Rule a rule that defines the value of each term in a
sequence with regard to its position.
nth Term Rule Also known as the position to term rule.
Uses algebra to work out the term given the position.
π The position of the nth term.
Position 1 2 3 4 β¦ π
Sequence 7 11 15 19 β¦ ππ + π
nth term rule
18. Sequences
Examples:
09/06/2023
eg1 Use the nth term rule to find
the first four terms.
ππ
eg2 Use the nth term rule to find
the first four terms.
ππ + π
Try Use the nth term rule to find
the first four terms.
ππ
Try Use the nth term rule to find
the first four terms.
ππ β π
π 1 2 3 4
2π 2 4 6 8
π 1 2 3 4
5π 5 10 15 20
π 1 2 3 4
2π + 4 6 8 10 14
π 1 2 3 4
5π β 3 2 7 12 17
19. Task 2:
1 Find the first 4 terms of each sequence.
a 3π b 4π c 4π + 1
d 4π + 7 e 4π β 10 f π β 10
3, 6, 9, 12 4, 8, 12, 16 5, 9, 13, 17
11, 15, 19, 23 β6, β2, 2, 6 β9, β8, β7, β6
g π + 10 h 1
2
π + 10 i 1
2
π β 2
11, 12, 13, 14 10.5, 11, 11.5, 12 β1.5, β1, β0.5, 0
2 Match the rule to the sequence.
9, 12, 15, 18 7, 8, 9, 10 6, 12, 18, 24 9, 15, 21, 27
6π π + 6 6π + 3 3π + 6
3 Find the first 4 terms of each sequence.
a β2π b 3 β 2π c 3 β 4π
β2, β4, β6, β8 1, β1, β3, β5 β1, β5, β9, β13
d π2 e π3 f 3π
1, 4, 9, 16 1, 8, 27, 64 3, 9, 27, 81
23. Sequences 3
Starter:
09/06/2023
Sequences
Which sequences below are linear?
1) 2, 5, 8, 11 β¦
2) 24, 19, 14, 9 β¦
3) 3, 6, 12, 24 β¦
4) 120π₯, 60π₯, 30π₯, 15π₯ β¦
Write the term to term rule each
sequence.
1) 4, 14, 24, 34 β¦
2) 1, 4, 16, 64 β¦
Use the position to term rule to write
the first four terms of the sequence.
ππ β π
Use the nth term rule to find the 8th
term of the sequence.
ππ β ππ
24. Sequences 3
Starter:
09/06/2023
Sequences
Which sequences below are linear?
1) 2, 5, 8, 11 β¦ Yes
2) 24, 19, 14, 9 β¦ Yes
3) 3, 6, 12, 24 β¦ No
4) 120π₯, 60π₯, 30π₯, 15π₯ β¦ No
Write the term to term rule each
sequence.
1) 4, 14, 24, 36 β¦ + 10
2) 1, 4, 16, 64 β¦ Γ 4
Use the position to term rule to write
the first four terms of the sequence.
ππ β π
Use the nth term rule to find the 8th
term of the sequence.
ππ β ππ
3, 8, 13, 18 β¦ 20
25. Sequences 3
Discussion:
09/06/2023
What is the nth term rule for this sequence?
6 12 18 24 β¦
+6 +6 +6 +6
Position (π) 1 2 3 4 β¦ π
Sequence 6 12 18 24 β¦ 6π
What is the nth term rule for this sequence?
4 10 16 22 β¦
+6 +6 +6 +6
Position (π) 1 2 3 4 β¦ π
Sequence 4 10 16 20 β¦ 6π β 2
26. Sequences 3
Discussion:
09/06/2023
What is the nth term rule for this sequence?
9 15 21 27 β¦
+6 +6 +6 +6
Position (π) 1 2 3 4 β¦ π
Sequence 9 15 21 27 β¦ 6π + 3
27. Sequences 3
Examples:
09/06/2023
eg1 Find the nth term rule for
π, π, ππ, ππ β¦
eg2 Find the nth term rule for
π, π, π, π β¦
Try Find the nth term rule for
π, π, π, ππ β¦
Try Find the nth term rule for
π, π, βπ, βπ β¦
5 8 11 14 2 5 8 11
8 6 4 2 6 2 -2 -6
+3 +3 +3
ππ 3 6 9 12
+2
ππ + π
+3 +3 +3
ππ 3 6 9 12
-1
ππ β π
-2 -2 -2
βππ β2 β4 β6 β8
+10
βππ + ππ
-4 -4 -4
βππ β4 β8 β12 β16
+10
βππ + ππ
28. Find the nth term rule for the following sequences.
a 3, 5, 7, 9 ... b 4, 6, 8, 10 ... c 2, 4, 6, 8 β¦
d 5, 10, 15, 20 β¦ e 2, 7, 12, 17 β¦ f 7, 12, 17, 22 β¦
g -2, 3, 8, 13 β¦ h -4, 6, 16, 26 β¦ i -40, 60, 160, 260 β¦
j 2, -1, -4, -7 β¦ k 2, -2, -6, -10 β¦ l 4, -4, -12, -20 β¦
2
Match the sequences to
the nth term rule.
1 5, 7, 9, 11 β¦
5, 8, 11, 14 β¦
4, 5, 6, 7 β¦
3π + 2
2π + 3
π + 3
Find the nth term rule of the sequence.
3
Is Jasper correct for the
sequence 10, 14, 18, 22β¦?
Explain
5
The nth term
rule is π + 4
Find the nth term rule for
1
2
,
2
5
,
3
8
,
4
11
β¦
6
2π + 1 2π + 2 2π
5π 5π β 3 5π + 2
5π β 7 10π β 14 100π β 140
β3π + 5 β4π + 6 β8π + 12
3π β 1
A sequence has a T2T rule
of +6. The 9th term is 57.
Find the nth term rule.
4
6π + 3
4π + 6
π
3π β 1