Sigma Notation

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Sigma Notation

• A compact way of defining a series
• A series is the sum of a sequence

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Sigma - A Greek letter the sum of
end term r4
the sum of the first 4 terms
start term r1
Make r1, r2, r3, and r4
1 2 3 4
10
3
the sum of
the sum of the first 6 terms
end term r6
start term r1
Make r1, r2, , r6
3 6 9 12 15 18 63
4
the sum of
end term r5
the sum of the first 5 terms
start term r1
Make r1, r2, ...., r 5
3 7 11 15 19 55
5
the sum of
the sum of the first 3 terms
end term r3
start term r1
Make r1, r2, r3
7² 9² 11² 49 81
121 251
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Working in reverse -
Write this series in sigma notation
1 4 9 16 25
1² 2² 3² 4² 5²
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Working in reverse -
Write this series in sigma notation
3 6 11 18 27
(12) (42) (92) (162) (252)
(1² 2) (2²2) (3²2) (4²2) (5²2)
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Exercise 6B Worked Solutions
1. Write down all the terms of the series
1² 2² 3² 4² 5² 1 4 9 16 25
55
(a)
(31-1)(32-1) (33-1) (34-1) (35-1)
(36-1) 2 5 8 11 14 17 57
(b)
(21²3) (22²3) (23²3) (24²3) 5 11
21 35 72
(c)