How do you tell whether the sequence #1, 2, 4, 7, 11# is arithmetic?

1 Answer
Mar 31, 2017

It is not an arithmetic sequence.

Explanation:

In an arithmetic sequence, the difference between a term and its immediately preceding term is always same.

Let use see here,

#2-1=1#

#4-2=2#

#7-4=3#

#11-7=4#

Here the difference is continuously increasing

Hence, it is not an arithmetic sequence.

Note: In an geometric sequence, the ratio of a term to its immediately preceding term is always same. This is not the case here as #2/1=2#, #4/2=2# but #7/4!=2# and #11/7!=2#. Hence, it is not a geometric sequence too