Question

Given the arithmetic sequence an = −5 + 3(n − 1), what is the domain for n?

Answer 1

Domain for n is All integers where n ≥ 1.

Explanation:

Given the arithmetic sequence

`a_n=-5+3(n-1)`

In arithmetic sequence,
`a_n=a+(n-1)d`

where a is first term.

d is common difference.

n is number of terms.

Now, in given sequence recursive formula for nth term is

`a_n=-5+3(n-1)`

the number of term is n and it belongs to natural number.

Hence, domain for n is All integers where n ≥ 1.

Answer 2

domain is the numbers you can use
the n stands for the which term

like 1st term, 2nd term, 3rd term, etc

so it makes sense that n is the set of all natural numbers (also called the set of counting numbers)