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Find the tenth term in the following geometric sequence. 8, 4, 2, 1, . . .

a) 13

b) 0.0078

c) 0.0156

d) 12.5

User Maholtz
by
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1 Answer

1 vote

Answer:

c) 0.0156

Explanation:

The general term a[n] of a geometric sequence is given in terms of the first term a[1] and common ratio r as ...

a[n] = a[1]r^(n-1)

The given sequence has an initial term of a[1]=8 and a common ratio of 4/8=1/2. Then the general term is ...

a[n] = 8(1/2)^(n-1)

The 10th term is then ...

a[10] = 8(1/2)^(10-1) = 8(1/2)^9 = 8/512

a[10] = 0.015625 ≈ 0.0156

User Offeltoffel
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