Q:

Chenoa starts with $250 in her savings account. Each month she adds $15.Which recursive function rule models the total amount in Chenoa’s savings account at the end of each month?A)an=250⋅an−1 and a1=15B)an=15⋅an−1 ​ and a1=250C)an=15+an−1 ​ and a1=250D)an=250+an−1 and a1=15

Accepted Solution

A:
Chenoa starts with $250 in her saving account and each month she adds $15 in her saving account.Therefore, we obtain a sequence as:250, (250+15), (250+15+15),...250, 265, 280,....So, we get the first term ([tex] a_{1} [/tex]) as 250.Now , we can clearly observe that the first term is 250 and second term is obtained by adding 15 to the first term that is 265 and so on.Similarly in an arithmetic progression, last term is [tex] a_{n} [/tex] and its previous term is [tex] a_{n-1} [/tex]. Similarly, [tex] a_{n} [/tex] will be obtained by adding 15 to its previous term [tex] a_{n-1} [/tex].So, [tex] a_{n}=15+a_{n-1} [/tex] and [tex] a_{1} [/tex]=250.Therefore, Option C is correct.