Question

Which recursive formula can be used to represent the sequence 2,6,10,14,18...?

Answer 1

Answer:

a(1) = 2

a(n) = a(n-1)+4

Step-by-step explanation:

Using the given arithmetic sequence,

a1 is 2

a2 is 6

a3 is 10

a4 is 14

a5 is 18

and to get from a1 to a2 you have to +4, to get from a2 to a3 you have to +4 and so on.

In a reclusive formula you need to find two pieces of information:

1. The first term of the sequence

2. The pattern rule to get any term from the term that comes before it

Using the given sequence, the first term is 2 and the rule to get any term from its previous term is +4.

So, putting that information in the form of a recursive formula will read as the following:

an+1 = an+4

a1 = 2, n is greater or equal to 1 (n is an interger)

Which can be rearranged to

a(1) = 2

a(n) = a(n-1)+4