The document discusses the concepts of sequences and series in mathematics. It begins by defining an arithmetic sequence as a sequence where the difference between consecutive terms is constant. The general form of an arithmetic sequence is given as U1, U2, U3, ..., Un where Un = a + (n-1)b, with a as the first term and b as the common difference. It further explains that the sum of terms in an arithmetic sequence is called an arithmetic series. An example is worked through to find the formula for the n-th term and a specific term in a given arithmetic sequence. Sigma notation for writing sequences and series is also introduced.
3. Hal.: 3 BARISAN DAN DERET AdaptifHal.: 3
Pola Barisan dan Deret Bilangan
Kompetensi Dasar :
Menerapkan konsep barisan dan deret aritmatika
Indikator :
1. Nilai suku ke- n suatu barisan aritmatika ditentukan
menggunakan rumus
2. Jumlah n suku suatu deret aritmatika ditentukan dengan
menggunakan rumus
4. Hal.: 4 BARISAN DAN DERET AdaptifHal.: 4
The Pattern of Sequence and Series Number
Basic Competence:
Applying the concept of arithmetic sequence and
series
Indicator :
1. The value of n-th term in an arithmetic sequence is defined
by formula
2. The sum of n in term of arithmetic sequence is defined by
formula
5. Hal.: 5 BARISAN DAN DERET AdaptifHal.: 5
Saat mengendarai motor, pernahkah kalian mengamati
speedometer pada motor tersebut?
Pada speedometer terdapat angka-angka 0,20, 40, 60, 80, 100,
dan 120 yang menunjukkan kecepatan motor saat kalian
mengendarainya. Angka-angka ini berurutan mulai dari
yang terkecil ke yang terbesar dengan pola tertentu sehingga
membentuk sebuah pola barisan
Pola Barisan dan Deret Bilangan
6. Hal.: 6 BARISAN DAN DERET AdaptifHal.: 6
When you ride a motor cycle, have you ever look at the
speeedometer?
In speedometer,there are numbers of 0,20, 40, 60, 80, 100, and
120 which show the speed of your motor cycle. These numbers
are un order, starts from the smallest to the biggest with certain
pattern, so that it forms a pattern of sequence
The Pattern of Sequence and Series Number
7. Hal.: 7 BARISAN DAN DERET AdaptifHal.: 7
Bayangkan anda seorang penumpang taksi. Dia harus membayar biaya buka pintu
Rp 15.000 dan argo Rp 2.500 /km.
15.000 17.500 20.000 22.500 …….
Buka pintu 1 km 2 km 3 km 4 km
Pola Barisan dan Deret Bilangan
8. Hal.: 8 BARISAN DAN DERET Adaptif
Imagine that you are a taxi passenger. You have to pay the starting fee Rp 15.000
and it charge Rp 2.500 /km.
15.000 17.500 20.000 22.500 …….
Starting fee 1 km 2 km 3 km 4 km
The Pattern of Sequence and Series Number
9. Hal.: 9 BARISAN DAN DERET Adaptif
NOTASI SIGMA
Konsep Notasi Sigma
Perhatikan jumlah 6 bilangan ganjil pertama berikut:
1 + 3 + 5 + 7 + 9 + 11 ……….. (1)
Pada bentuk (1)
Suku ke-1 = 1 = 2.1 – 1
Suku ke-2 = 3 = 2.2 – 1
Suku ke-3 = 5 = 2.3 – 1
Suku ke-4 = 7 = 2.4 – 1
Suku ke-5 = 9 = 2.5 – 1
Suku ke-6 = 11 = 2.6 – 1
Secara umum suku ke-k pada (1) dapat dinyatakan
dalam bentuk 2k – 1, k ∈ { 1, 2, 3, 4, 5, 6 }
10. Hal.: 10 BARISAN DAN DERET Adaptif
SIGMA NOTATION
The Concept of Sigma Notation
Look at the sum of the first sixth odd number below:
1 + 3 + 5 + 7 + 9 + 11 ……….. (1)
In the form(1)
The 1st
term = 1 = 2.1 – 1
The 2nd
term= 3 = 2.2 – 1
The 3rd
term = 5 = 2.3 – 1
The 4th
term = 7 = 2.4 – 1
The 5th
term = 9 = 2.5 – 1
The 6th
term = 11 = 2.6 – 1
Generally, the k-th term in (1) can be stated in the form of
2k – 1, k ∈ { 1, 2, 3, 4, 5, 6 }
11. Hal.: 11 BARISAN DAN DERET Adaptif
NOTASI SIGMA
Dengan notasi sigma bentuk penjumlahan (1) dapat
ditulis :
∑=
=+++++
6
1k
1)-(2k1197531
12. Hal.: 12 BARISAN DAN DERET Adaptif
SIGMA NOTATION
In Sigma notation, the addition form (1) can be
written as:
∑=
=+++++
6
1k
1)-(2k1197531
13. Hal.: 13 BARISAN DAN DERET Adaptif
Bentuk ∑
=
−
6
1
)12(
k
k
dibaca “sigma 2k – 1 dari k =1 sampai dengan 6”
atau “jumlah 2k – 1 untuk k = 1 sd k = 6”
1 disebut batas bawah dan
6 disebut batas atas,
k dinamakan indeks
(ada yang menyebut variabel)
∑
=
−−
9
4
)1)3(2(
k
k ∑
=
−
9
4
)72(
k
k
NOTASI SIGMA
14. Hal.: 14 BARISAN DAN DERET Adaptif
In the form
of
∑
=
−
6
1
)12(
k
k
It is read “sigma 2k – 1 from k =1 to 6” or “the sum
of 2k – 1 for k = 1 sd k = 6”
1 is called lower limit and
6 is called upper limit,
k is called index (some people
called it variable)
∑
=
−−
9
4
)1)3(2(
k
k ∑
=
−
9
4
)72(
k
k
SIGMA NOTATION
17. Hal.: 17 BARISAN DAN DERET Adaptif
Nyatakan dalam bentuk sigma
1. a + a2
b + a3
b2
+ a4
b3
+ … + a10
b9
∑ −
=
10
1k
)1kbk(a
)142()132()122()112()12(
4
1
+⋅++⋅++⋅++⋅=+∑=k
k
Contoh:
249753 =+++=
Hitung nilai dari:
NOTASI SIGMA
18. Hal.: 18 BARISAN DAN DERET Adaptif
Stated into sigma form
1. a + a2
b + a3
b2
+ a4
b3
+ … + a10
b9
∑ −
=
10
1k
)1kbk(a
)142()132()122()112()12(
4
1
+⋅++⋅++⋅++⋅=+∑=k
k
Example:
249753 =+++=
Define the value of
SIGMA NOTATION
19. Hal.: 19 BARISAN DAN DERET Adaptif
NOTASI SIGMA
nn
n
1n
bCabC...baCbaCbaCa n
1n
33nn
3
22nn
2
1nn
1
n
++++++ −
−
−−−
∑
=
−
n
0r
rrnn
r
baC
2. (a + b)n
=
20. Hal.: 20 BARISAN DAN DERET Adaptif
SIGMA NOTATION
nn
n
1n
bCabC...baCbaCbaCa n
1n
33nn
3
22nn
2
1nn
1
n
++++++ −
−
−−−
∑
=
−
n
0r
rrnn
r
baC
2. (a + b)n
=
21. Hal.: 21 BARISAN DAN DERET Adaptif
Sifat-sifat Notasi Sigma :
, Untuk setiap bilangan bulat a, b dan n
.....1 321
1
n
n
k
aaaaak +++=∑=
∑∑ ==
=
n
mk
n
mk
akCCak.2
∑∑∑ ===
+=+
n
mk
n
mk
n
mk
bkakbkak )(.3
∑∑
+
+==
−
pn
pmk
n
mk
pakak.4
CmnC
n
mk
)1(.5 +−=∑=
∑∑∑ ==
−
=
=+
n
mk
n
pk
p
mk
akakak
1
.6
0.7
1
=∑
=
=
m
mk
ak
NOTASI SIGMA
22. Hal.: 22 BARISAN DAN DERET Adaptif
The properties of sigma notation :
, For every integer a, b and n
.....1 321
1
n
n
k
aaaaak +++=∑=
∑∑ ==
=
n
mk
n
mk
akCCak.2
∑∑∑ ===
+=+
n
mk
n
mk
n
mk
bkakbkak )(.3
∑∑
+
+==
−
pn
pmk
n
mk
pakak.4
CmnC
n
mk
)1(.5 +−=∑=
∑∑∑ ==
−
=
=+
n
mk
n
pk
p
mk
akakak
1
.6
0.7
1
=∑
=
=
m
mk
ak
SIGMA NOTATION
23. Hal.: 23 BARISAN DAN DERET Adaptif
NOTASI SIGMA
Contoh1:
Tunjukkan bahwa
Jawab :
∑∑ ==
+=+
3
1
3
1
)24()24(
jk
ji
30)33.4()22.4()21.4()24(
3
1
=+++++=+∑=i
i
30)23.4()22.4()21.4()24(
3
1
=+++++=+∑=j
j
24. Hal.: 24 BARISAN DAN DERET Adaptif
SIGMA NOTATION
Example 1:
Show that
Answer :
∑∑ ==
+=+
3
1
3
1
)24()24(
jk
ji
30)33.4()22.4()21.4()24(
3
1
=+++++=+∑=i
i
30)23.4()22.4()21.4()24(
3
1
=+++++=+∑=j
j
26. Hal.: 26 BARISAN DAN DERET Adaptif
SIGMA NOTATION
∑∑ ==
+
6
4
2
3
1
2
66
kk
kk
∑∑∑∑ ====
==+
6
1
2
6
1
2
6
4
2
3
1
2
6666
kkkk
kkkk
Define the value of
Example 2 :
Answer:
= 6 (12
+22
+ 32
+ 42
+ 52
+ 62
)
= 6 (1 + 4 + 9 + 16 + 25 + 36)
= 6.91 = 546
27. Hal.: 27 BARISAN DAN DERET Adaptif
BARISAN DAN DERET ARITMATIKA
Bilangan-bilangan berurutan seperti pada speedometer memiliki selisih yang
sama untuk setiap dua suku berurutannya sehingga membentuk suatu barisan
bilangan
Barisan Aritmatika adalah suatu barisan dengan selisih (beda)
dua suku yang berurutan selalu tetap
Bentuk Umum :
U1, U2, U3, …., Un
a, a + b, a + 2b,…., a + (n-1)b
Pada barisan aritmatika,berlaku Un – Un-1 = b sehingga Un= Un-1 + b
28. Hal.: 28 BARISAN DAN DERET Adaptif
ARITHMETIC SEQUENCE AND SERIES
The orderly numbers like in speedometer have the same difference for
every two orderly term, so it forms a sequence
Arithmetic sequence is sequence with difference two orderly term
constant
The general form is :
U1, U2, U3, …., Un
a, a + b, a + 2b,…., a + (n-1)b
In arithmetic sequence, we have Un – Un-1 = b, so Un= Un-1 + b
30. Hal.: 30 BARISAN DAN DERET Adaptif
If you start arithmetic sequence with the first term a and difference b, then
you will get this following sequence
The n-th term of arithmetic sequence is Un = a + ( n – 1 )b
Where Un = n-th term
a = the first term
b = difference
n = the term’s quantity
ARITHMETIC SEQUENCE AND SERIES
a a + b a + 2b a + 3b …. a + (n-1)b
31. Hal.: 31 BARISAN DAN DERET AdaptifHl.: 31
BARISAN DAN DERET ARITMATIKA
32. Hal.: 32 BARISAN DAN DERET Adaptif
If every term of arithmetic sequence is added, then we will get arithmetic
series.
Arithmetic series is the sum of terms of arithmetic sequence
General form :
U1 + U2 + U3 + … + Un atau
a + (a +b) + (a+2b) +… + (a+(n-1)b)
The formula of the sum of the first term in arithmetic series is
Where S = the sum of n-th term
n = the quantity of term
a = the first term
b = difference
= n-th term
ARITHMETIC SEQUENCE AND SERIES
( )bna
n
Sn )1(2
2
−+=
34. Hal.: 34 BARISAN DAN DERET Adaptif
Known: the sequence of 5, -2, -9, -16,…., find:
a.The formula of n-th term
b.The 25th
term
Answer:
The difference of two orderly terms in sequence 5,-2, -9,-16 ,…is constant, b= -7,
so that the sequence is an arithmetic sequence
a.The formula of the n-th term in arithmetic sequence is
Un = 5 + ( n – 1 ). -7
Un = 5 + - 7n + 7
Un = -7n + 12
b. The 25th
term of arithmetic sequence is : U12 = - 7.12 + 12
= - 163
ARITHMETIC SEQUENCE AND SERIES
35. Hal.: 35 BARISAN DAN DERET Adaptif
Barisan geometri adalah suatu barisan dengan
pembanding (rasio) antara dua suku yang
berurutan selalu tetap.
Ada selembar kertas biru, akan dipotong-potong menjadi dua bagian.
BARISAN DAN DERET GEOMETRI
36. Hal.: 36 BARISAN DAN DERET Adaptif
Geometric sequence is a sequence which has
the constant ratio between two orderly term
There is blue paper. It will cut into two pieces
GEOMETRIC SEQUENCE AND SERIES
38. Hal.: 38 BARISAN DAN DERET Adaptif
Look at the paper part that form a sequence
Every two orderly terms of the sequence have the same ratio
It seems that the ratio of every two orderly terms in the sequence is
always constant. The sequence like this is called geometric
sequence and the comparison of every two orderly term is called
ratio (r)
1 2 4
U1 U2 U3
2....
12
3
1
2
====
−n
n
U
U
U
U
U
U
GEOMETRIC SEQUENCE AND SERIES
39. Hal.: 39 BARISAN DAN DERET AdaptifHal.: 39
BARISAN DAN DERET GEOMETRI
40. Hal.: 40 BARISAN DAN DERET Adaptif
Geometric sequence is a sequence which have constant
ratio for two orderly term
General form: U1, U2, U3, …., Un atau
a, ar, ar2
, …., arn-1
In geometric sequence
If you start the geometric sequence with the first term a
and the ratio is r, then you get the following sequence
GEOMETRIC SEQUENCE AND SERIES
r
U
U
n
n
=
−1
1. −= nn UrsehinggaU
41. Hal.: 41 BARISAN DAN DERET Adaptif
Suku ke-n barisan Geometri adalah :
BARISAN DAN DERET GEOMETRI
42. Hal.: 42 BARISAN DAN DERET Adaptif
The n-th term of geometric sequence is :
GEOMETRIC SEQUENCE AND SERIES
Start With the
first term a
Multiply with
ratio r
Write the
multiplication
result
43. Hal.: 43 BARISAN DAN DERET Adaptif
BARISAN DAN DERET GEOMETRI
Hubungan suku-suku barisan geometri
Seperti dalam barisan Aritmatika hubungan antara suku
yang satu dan suku yang lain dalam barisan geometri dapat
dijelaskan sebagai berikut:
Ambil U12 sebagai contoh :
U12 = a.r11
U12 = a.r9
.r2
= U10. r2
U12 = a.r8
.r3
= U9. r3
U12 = a.r4
.r7
= U5. r7
U12 = a.r3
.r8
= U4.r8
Secara umum dapat dirumuskan bahwa :
Un = Uk. rn-k
44. Hal.: 44 BARISAN DAN DERET Adaptif
GEOMETRIC SEQUENCE AND SERIES
The relation of terms in geometric sequence
Like in arithmetic sequence, the relation between terms in
geometric sequence can be explained as follows:
Take U12 as example :
U12 = a.r11
U12 = a.r9
.r2
= U10. r2
U12 = a.r8
.r3
= U9. r3
U12 = a.r4
.r7
= U5. r7
U12 = a.r3
.r8
= U4.r8
Generally, it can be formulated
Un = Uk. rn-k
46. Hal.: 46 BARISAN DAN DERET Adaptif
GEOMETRIC SEQUENCE AND SERIES
Geometric series is the sum of terms in geometric sequence
General form
U1 + U2 + U3 + …. + Un
a + ar + ar2
+ ….+ arn-1
The formula of the n sum of the first term in geometric series is
1,
1
)1(
<
−
−
= r
r
ra
S
n
n
48. Hal.: 48 BARISAN DAN DERET Adaptif
GEOMETRIC SEQUENCE AND SERIES
Known sequence 27, 9, 3, 1, …..find
a.The formula of the n-th term
b. The 8th
term
Answer:
The ratio of two orderly terms in sequence 27,9,3, 1, …is constant,
so that the sequence is a geometric sequence
a. The formula of the n-th term in geometric sequence is
3
1
=r
1
3
1
27
−
=
n
nU
113
)3.(3 −−
= n
13
3.3 +−
= n
n−
= 4
3
49. Hal.: 49 BARISAN DAN DERET Adaptif
GEOMETRIC SEQUENCE AND SERIES
b. The 8th term of geometric sequence is
84
8 3 −
=U
4
3−
=
81
1
=
n
nU −
= 4
3
50. Hal.: 50 BARISAN DAN DERET Adaptif
Deret geometi tak hingga adalah deret geometri yang banyak suku-
sukunya tak hingga.
Jika deret geometri tak hingga dengan -1 < r < 1 , maka jumlah deret
geometri tak hingga tersebut mempunyai limit jumlah (konvergen).
Untuk n = ∞ , rn
mendekati 0
Sehingga S∞ =
Dengan S∞ = Jumlah deret geometri tak hingga
a = Suku pertama
r = rasio
Jika r < -1 atau r > 1 , maka deret geometri tak hingganya akan divergen,
yaitu jumlah suku-sukunya tidak terbatas
Deret Geometri tak hingga
r
a
−1
r
ra
Sn
n
−
−
=
1
)1(
BARISAN DAN DERET GEOMETRI
51. Hal.: 51 BARISAN DAN DERET Adaptif
Infinite geometric series is a geometric series which has infinite terms.
If infinite geometric series is -1 < r < 1 , then the sum of geometric series
has sum limit (convergent).
For n = ∞ , rn
is close to 0
So S∞ =
With S∞ = the sum of infinite geometric series
a = the first term
r = ratio
If r < -1 or r > 1 , then the infinite geometric series will be divergent,
means the sum of terms is not limited
Infinite Geometric Series
r
a
−1
r
ra
Sn
n
−
−
=
1
)1(
GEOMETRIC SEQUENCE AND SERIES
52. Hal.: 52 BARISAN DAN DERET Adaptif
1. Hitung jumlah deret geometri tak hingga : 18 + 6 + 2 + … . .
Contoh :
3
1
2
3
1
2
===
u
u
u
u
r
BARISAN DAN DERET GEOMETRI
27
3
2
18
3
1
1
18
1
==
−
=
−
=∞
r
a
s
Jawab :
a = 18 ;
53. Hal.: 53 BARISAN DAN DERET Adaptif
1. Find the sum of infinite geometric series : 18 + 6 + 2 + … . .
Example :
3
1
2
3
1
2
===
u
u
u
u
r
GEOMETRIC SEQUENCE AND SERIES
27
3
2
18
3
1
1
18
1
==
−
=
−
=∞
r
a
s
Answer :
a = 18 ;
54. Hal.: 54 BARISAN DAN DERET Adaptif
2. Sebuah bola elastis dijatuhkan dari ketinggian 2m. Setiap kali memantul dari
lantai, bola mencapai ketinggian ¾ dari ketinggian sebelumnya. Berapakah
panjang lintasan yang dilalui bola hingga berhenti ?
BARISAN DAN DERET GEOMETRI
Lihat gambar di samping!
Bola dijatuhkan dari A, maka AB dilalui satu kali,
selanjutnya CD, EF dan seterusnya dilalui dua
kali. Lintasannya membentuk deret geometri
dengan a = 3 dan r = ¾
Panjang lintasan = 2 S∞ - a
2
4
1
2
2
2
4
3
1
2
2
1
2
−
=
−
−
=
−
−
= a
r
a
= 14
Jadi panjang lintasan yang dilalui bola adalah14 m
55. Hal.: 55 BARISAN DAN DERET Adaptif
2. An elastic ball is drop from the height of 2m. Every time it bounce from the
floor, it has ¾ of the previous height. How long is the route that will be passed
by the ball until it stop?
GEOMETRIC SEQUENCE AND SERIES
Look at the picture!
The ball is drop from A, so AB is passed only
once. Then CD, EF, etc is passed twice. The
route is in geometric series with a = 3 and r = ¾
the length of the route is= 2 S∞ - a
2
4
1
2
2
2
4
3
1
2
2
1
2
−
=
−
−
=
−
−
= a
r
a
= 14
So, the route length that pass by the ball is 14 m