Question

What fomula can be used to describe the sequence? -2/3,-4,-24,-144

Answer 1

This is a geometric sequence with n th term formula

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

where r is the common ratio and
`a_(1)` the first term

here
`a_(1)` = -
`(2)/(3)` and

r =
`(-144)/(-24)` =
`(-24)/(-4)` = 6

`a_(n)` = -
`(2)/(3)`
`(6)^(n-1)`

or in terms of x

f(x) = -
`(2)/(3)`
`(6)^(x-1)`