Question

Determine if the sequence below is arithmetic or geometric and determine the common difference / ratio in simplest form. 4, 2, 1, ...

I need the help now ​

Answer 1

geometric with r =
`(1)/(2)`

Explanation:

An arithmetic sequence has a common difference (d) between consecutive terms

2 - 4 = - 2

1 - 2 = - 1

Then d is not common , not an arithmetic sequence

A geometric sequence has a common ratio (r ) between consecutive terms

2 ÷ 4 = 0.5

1 ÷ 2 = 0.5

Then common ratio r =
`(1)/(2)`

Thus sequence is geometric