Question

Ind the formula for the geometric sequence 4, -8, 16, -32,

Answer 1

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

Explanation:

the nth term of a geometric sequence is

`a_(n)` = a₁
`(r)^(n-1)`

where a₁ is the first term and r the common ratio

here a₁ = 4 and r =
`(a_(2) )/(a_(1) )` =
`(-8)/(4)` = - 2 , then

nth term formula is

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