Question

Write an explicit formula for an, the n^th term of the sequence 22, 20, 18, ....

Answer 1

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

Explanation:

The given sequence is 22, 20, 18, ...

We need to find the explicit formula for an.

First term is 22

Second term = 20

Third term = 18

We can write the formula as :

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

Where

a is 22

d is common difference = 20-22 = -2

Forth term will be :

`a_4=22+(4-1)(-2)\\\\=22-6\\\\=16`

Hence, the formula is
`a_n=a+(n-1)d`.