For an arithmetic progression with first term and common difference

MATHEMATICS · Subjective · A Level · Mathematics · Sequences and series · Sequences and series

Problem

For an arithmetic progression with first term aa and common difference dd, prove that the formula Sn=n2 [2a+(n−1)d]S_n = \dfrac{n}{2}\,[2a + (n-1)d] holds even when nn is odd.

Related theory

Browse the problem library