Mathematics for IGCSE & O level - Sequences (Section 3 - No. 24)
Which of these sequence is *not* a geometric sequence?
1, 2, 4, 8,...
2, 6, 18, 54, ...
1, 3, 5, 7, ...
3, 9, 27, 81,...
解释
Geometric sequences have a common ratio. A linear sequence does not have a common ratio.