Question

Write the explicit formula that represents the geometric sequence -2,8,-32,128.

Can u help me if u know the answer pls

Answer 1

`a_(n)` = - 2
`(-4)^(n-1)`

Explanation:

The n th term ( explicit formula ) for a geometric sequence is

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

where a is the first term and r the common ratio

Here a = - 2 and r = 8 ÷ - 2 = - 4, thus

`a_(n)` = - 2
`(-4)^(n-1)`