If the sum of the first terms of an AP is

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

Problem

11. If the sum of the first

n

terms of an AP is

4 n-n^{2}

, what is the first term (that is

\mathrm{S}_{1}

)? What is the sum of first two terms? What is the second term? Similarly, find the 3rd, the 10th and the

n

th terms. (1) what is the first term (that is

\mathrm{S}_{1}

)? (2) What is the sum of first two terms? (3) What is the second term? (4) find the 3rd term (5) find the 10th term (6) find the

n

th term