Write an equation for the nth term of the geometric sequence. Then find a9. 486, 162, 54, 18, ...

Answer 1

it's a geometric sequence with common ratio =r = 1/3.

a1 = 486,

a2 = 162,

a3 = 54,

a4 = 18

a5 = 6

a6 =2

a7 = 2/3

a8 = 2/9,

a9 = 2/27 = 0.04074074

an = a1(r^(n-1))

a9 = 486(1/3(^8 = 486/3^8 = 486/6561 = 0.074074074