Question

In: Math

A geometric sequence has the first term a1 = −3 and common ratio r = 1/2 . What is the 8th term?

A geometric sequence has the first term a1 = −3 and common ratio r = 1/2 . What is the 8th term?

Solutions

Expert Solution

Consider a geometric sequence with first term a1 = -3 and common ratio r = 1/2

Use the formula for nth term of a geometric sequence,,

an = a1 ∙ rn-1 ...... (1)

 

Substitute a1 = -3, r = 1/2 and n = 8 in the formula (1) and compute 8th term of given sequence,

a8= -3 × (1/2)8-1

     = -3 × 1/128

     = -3/128

 

Therefore, 8th term of given sequence is a3 = -3/128.


Therefore, 8th term of given sequence is a3 = -3/128.

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