Question

Recursive rule for an arithmetic sequence is a1=−3; an=an−1+7.

What is the iterative rule for this sequence?

Answer 1

an = 7n -10

Explanation:

In general, the iterative rule for an arithmetic sequence with first term a1 and common difference d is ...

... an = a1 + (n-1)d

Your sequence has a1 = -3, and d = 7, so the rule can be written ...

... an = -3 + 7(n -1)

and simplified to ...

... an = 7n -10