Question

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

Answer 1

Answer:

  c)  0.0156

Step-by-step 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