Find the 9th term of the geometric sequence:

Question

Find the 9th term of the geometric sequence:

1/2, 1/4, 1/8, ...

Answer 1

a1 = 1/2

a2 = 1/4

a3 = 1/8

a4 = 1/16

a5 = 1/32

a6 = 1/64

a7 = 1/128

a8 = 1/256

a9 = 1/512

an = a1(r^n-1)

an = (1/2)(1/2^8) = 1/2^9

a9 = 1/(2^9) = 1/512

common ratio = r = 1/2