Question

Write a recursive formula for the explicit formula.

A(n)= 9+ (n - 1)(-4)
Choose the correct formula below.

O A. A(n-1)= A(n) - 4; A(1)= 9

OB. A(n) = A(n-1) - 4; A(1)= 9

O C. A(n-1) = A(n) + 9; A(1)= - 4

OD. A(n) = A(n-1) + 9; A(1) = - 4

Answer 1

Answer: A

Explanation:

`A_n=9+(n-1)*(-4)\\\\A_1=9+(1-1)*(-1)=9+0=9\\\\A_(n-1)=9+((n-1)-1)*(-4)\\\\A_n-A_(n-1)=9+(n-1)*(-4)-(9+(n-2)*(-4))=-4n+4+4n-8=-4\\\\\boxed{A_n=A_(n-1)-4}\\\\\\Answer\ A`