What is the general term of the sequence #{10,-20,40,-80,....}#?

1 Answer
Oct 26, 2016

Answer:

General term of given sequence is #10xx(-2)^(n-1)#

Explanation:

Here the ratio between a term and its preceding term is constant as #-20/10=40/-20=-80/40=-2#

Hence it a geometric sequence with first term as #10# and common ratio as #-2#.

The general term of a geometric sequence with first term as #a# and common ratio as #r# is #axxr^(n-1)#.

Hence, general term of given sequence is #10xx(-2)^(n-1)#