Prove that the sum of the first terms of a geometric progression with first term and…

MATHEMATICS · Subjective · CBSE · Mathematics · Sequences and Series · Sequences and Series

Problem

Prove that the sum

S_n

of the first

n

terms of a geometric progression with first term

a

and common ratio

r\neq1

S_n=\dfrac{a(1-r^{n})}{1-r}.