Question

Select the correct rule for this Geometric Sequence:

3, 12, 48, 192, ...

Question 5 options:

A(n)=12−3n−1

A(n)=3⋅12n−1

A(n)=3⋅4n−1

A(n)=4⋅3n−1

A(n)=3+12n−1

Answer 1

see explanation

Explanation:

given the geometric sequence then the n th term rule is

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

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

here r =
`(192)/(48)` =
`(48)/(12)` = 4 and
`a_(1)` = 3, hence

`a_(n)` = 3 .
`4^(n-1)` ← third option