Question

write a recursive formula for $a_n$, the $n^{\text{th}}$ term of the sequence 20, 29, 38, 47, ....

answer attempt 1 out of 2

$a_1 = \square$

$a_n = \square$

Explanation:

Step1: Identify first term

The first term of the sequence is given as 20, so $a_1 = 20$.

Step2: Find common difference

Calculate the difference between consecutive terms: $29-20=9$, $38-29=9$, $47-38=9$. The common difference is 9.

Step3: Write recursive formula

For a recursive formula, each term is the previous term plus the common difference, valid for $n>1$.
$a_n = a_{n-1} + 9$

Answer:

$a_1 = 20$
$a_n = a_{n-1} + 9$ for $n>1$