Question

Write a recursive formula for the following arithmetic sequence.

−2, −6, −10, −14, ...

=a1
=anfor≥n2

Answer 1

Answer: A(n) = 2 - 4n

Explanation:

General formular of an A.P:

`a_(n) = a_(1) + (n - 1)d`

a_n » the nth term

a1 » first term, a1 is -2

n » number of terms

d » common difference, d = -6 - (-2) = -6+2 = -4

`a_(n) = - 2 + \{(n - 1) * - 4 \} \\ a_(n) = - 2 + ( - 4n + 4) \\ a_(n) = ( - 2 + 4) - 4n \\ a_(n) = 2 - 4n`