How do you find the explicit formula for the following sequence 2, 4, 6, 8,...?

1 Answer
Nov 23, 2017

a_n = a_1+2(n-1) = 2+2(n-1)an=a1+2(n1)=2+2(n1)

Explanation:

Each term is 2 greater than the term before it. Thus for any given term, a_nan, our equation is:

a_n = 2nan=2n

We can write this in a form closer to standard, by noting that a_1=2a1=2, so we can make it dependent on a_1a1..

a_n = a_1+2(n-1) = 2+2(n-1)an=a1+2(n1)=2+2(n1)