The first three terms of an arithmetic sequence are

MATHEMATICS · Multi-part · CBSE · Mathematics · Arithmetic Progressions · Arithmetic Progressions

Problem

u_1

5u_1 - 8

and

3u_1 + 8

. (1) Show that

u_1 = 4

. (2) Prove that the sum of the first

n

terms of this arithmetic sequence is a square number.