Question

The recursive formula for an arithmetic sequence is given below. What is the third term in the sequence?
a1=-9
an=3+a(n-1)

a. -6
b. -3
c. 3
d. 0

Answer 1

\(\large \mathbb{a_1 = -9}\)

\(\large \mathbb{a_n = 3 + a_{n-1}}\)

Answer 2

first find \(a_2\)
put \(n=2\) in the given recursive formula

Answer 3

\\(\large \mathbb{a_2 = 3 + a_{2-1}}\)
\\(\large \mathbb{~~~ = 3 + a_{1}}\)

Answer 4

plugin \(a_1\) value above,
similarly find the third term, \(a_3\), using \(a_2\) value