 Ask Remember Me? AdrianCavinder Posts: 55, Reputation: 1 Junior Member #1 Apr 16, 2012, 12:27 AM
A question on geometric sequences?
Hi, I am tutoring the UK curriculum for AS (11th grade) Level Mathematics and came upon this question which has stumped me. Any help would be appreciated.

An infinite geometric series has a first term a and sum to infinity b, where b ≠ 0. Prove that a lies between 0 and 2b.

Now I can work out that the StI is b = a/(1 - r) but Im not sure how to proceed from here. Any help would be most appreciated. Thanks.

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