A sequence is defined by .

MATHEMATICS · Multi-part · A Level · Mathematics · Sequences and series · Sequences and series

Problem

A sequence is defined by

u_n = \frac{71 - 7n}{2}

. (a) Prove that the sequence is arithmetic. (b) Find

u_1

and

d

. (c) Find

u_{75}

. (d) For what values of

n

are the terms of the sequence less than -200?