Question

For the following geometric sequence find the explicit formula. {12, -6, 3,. }.

Answer 1

`a_(n)` = 12
`(-(1)/(2)) ^(n-1)`

Explanation:

the explicit formula for a geometric sequence is

`a_(n)` = a₁
`(r)^(n-1)`

where a₁ is the first term and r the common ratio

here a₁ = 12 and r =
`(a_(2) )/(a_(1) )` =
`(-6)/(12)` = -
`(1)/(2)` , then explicit formula is

`a_(n)` = 12
`(-(1)/(2)) ^(n-1)`