Question

Find a formula for the nth termof the arithmetic sequence.First term 9Common difference -2an = [? ]n + []

Answer 1

Given:

First term 9

Common difference -2

Required:

Find a formula for the nth term of the arithmetic sequence.

Explanation:

The general formula for the nth term of the an arithmetic sequence is given by the formula:

$a_n=a+(n-1)d$

Where a = first term

d = common difference

Put a = 9 and d = -2 in the formula.

$\begin{gathered} a_n=9+(n-1)(-2) \\ a_n=9-2(n-1) \\ a_n=9-2n+2 \\ a_n=-2n+11 \end{gathered}$

Final Answer:

The nth term of the arithmetic sequence is

$a_n=-2n+11$