Question

Which is the 6th term of the geometric sequence 729,81,9,

Answer 1

`(1)/(81)`

Explanation:

The n th term of a geometric sequence is

`a_(n)` = a
`(r)^(n-1)`

where a is the first term and r the common ratio

r =
`(81)/(729)` =
`(9)/(81)` =
`(1)/(9)`

and a = 729, hence

`a_(6)` = 729 ×
`((1)/(9)) ^(5)`

= 729 ×
`(1)/(59049)` =
`(729)/(59049)` =
`(1)/(81)`

Answer 2

531,441 or 1/81

Explanation:

You get this answer by multiplying each term by 9. for example: 9x9 is 81 and 81x9 is 729.

Unless this is going backwords and its division. Then the answer will be 1/81.