Which of the following represents a geometric series (remember what a series is as opposed to a sequence)? 4, 12, 36, ... 4 + 12 + 36 + ... 4 + 12 + 20 + ... 4, 12, 20, ...

Question

asked Sep 4, 2020 79.4k views

1 Answer

Sangony · Answer 1 · 2020-09-09T15:36:51+0000

Answer:

4 + 12 + 36 + ...

Explanation:

4, 12, 36, ... is a geometric sequence, it has a common ratio of
r=(36)/(12)=(12)/(4)=3

When we add the terms of a geometric sequence we get a geometric series.

4+12+36+ ... is a geometric series, it has a common ratio of
r=(36)/(12)=(12)/(4)=3

4 + 12 + 20 + ... is not a geometric series because it has no common ratio

$(20)/(12)\\e (12)/(4)$

The second choice is correct