Expert: Ahmed Salami - 10/13/2010

Question
I need help on my geometry homework,the question says to
find the function rule for the following table
n: 1,2,3,4,5,6,
f: 9,13,17,21,25,29
I don't know how to solve it and have four more problems,
could you tell me how i can find the answer, thanks for your
help.

Answer
Hi Daniel,
The function f seems to be in arithmetic progression since its value increases constantly by 4 for any unit change in n.
The general form for an arithmetic progression is
f = a + (n-1)d
where a is the first term and d is the constant difference.
So,
f = 9 + (n-1)4
 = 9 + (4n - 4)
 = 4n + 5

Regards