Consider an AP with first term and common difference

MATHEMATICS · Multi-part · CBSE · Mathematics · Sequences and Series · Sequences and Series

Problem

Consider an AP with first term

2

and common difference

5

, and a GP with first term

2

and positive common ratio

r

. (i) If the sums of the first

4

terms of the two progressions are equal, find the value of

r

. (ii) For the value of

r

obtained in part (i), determine which of the two sums is larger when

n\ge 5

. Give a clear justification.