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Given the arithmetic sequence a_n=4+8(n-1), what is the domain for n?

Apr 28, 2017

Domain of $n$ is $\mathbb{N}$, the set of natural numbers.

Explanation:

In any sequence, arithmetic, geometric, or harmonic or any other,

$n$ represents number of terms, i.e. starting fromm ${a}_{1}$, then ${a}_{2}$ and so on till say ${a}_{n}$, which is ${n}^{t h}$ term.

As $n$ is used to count number of terms, it can take values of only natural numbers.

Hence domain of $n$ is $\mathbb{N}$, the set of natural numbers.

Here too $n \in \mathbb{N}$.