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7 votes
7 votes
Q4) Identify which of the following are geometric sequences and which are

not
(i) 2, 6, 18, 54.....
(ii) 25,5, 1,
(iii) 1, 4, 9, 16

User Xwrs
by
3.0k points

1 Answer

7 votes
7 votes

Answer:

(i) and (ii)

Explanation:

For a sequence to be geometric then the ratio r between consecutive terms must be common.

(1)

2, 6, 18, 54

6 ÷ 2 = 3

18 ÷ 6 = 3

54 ÷ 18 = 3

Here there is a common ratio r = 3 , then sequence is geometric

(ii)

25, 5, 1


image =
image and
image =
image

There is a common ratio r =
image , then sequence is geometric

(iii)

1, 4, 9, 16

4 ÷ 1 = 4

9 ÷ 4 = 2.25

16 ÷ 9 = 1.777..

There is no common ratio, then sequence is not geometric

User Zakk
by
3.0k points
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