Question

an arithmetic sequence is represented by the explicit formula a(n)=2+9(n-1).what is the recursive formula?

Answer 1

To start, what is a recursive formula?

Answer 2

a(n)=a(n-1)9

Answer 3

Now do you know what a explicit formula is?

Answer 4

I gtg. Here are links that state the problem pretty well.
If you have any questions ask around, and actually send people questions. Look around for some people with solving experience.
http://www.mathwords.com/r/recursive_formula.htm
http://www.mathwords.com/e/explicit_formula.htm
http://stackoverflow.com/questions/5766053/how-to-calculate-the-explicit-form-of-a-recursive-function