Question

Alex started a new social media account, which he uses to post pictures of cute animals. On the first day, he had only 8 followers. However, his account became popular very quickly and his number of followers tripled every day. Identify the recursive function that gives the number of followers he has after n days.

Answer 1

Answer:

$T_n = 3T_{n-1}$

Step-by-step explanation:

Given

$T_1 = 8$ -- First term

$r = 3$ --- rate

Required

Determine the recursive term

We have:

$T_1 = 8$

The second term to the nth term is:

$T_2 = T_1 * 3 = 8 * 3 = 24$

$T_3 = T_2 * 3 = 24 * 3 = 72$

$T_4 = T_3 * 3 = 72 * 3 = 216$

Using the above yardstick:

$T_n = T_{n-1} * 3$

$T_n = 3T_{n-1}$

Answer 2

Answer:

4.Let the required function be denoted by f(n) , where n denotes the nth day after Alex started a new social media account.

On day 1, the number of Alex’s followers is 8. Hence f(1) = 8.

Subsequently, the number of Alex’s followers tripled every day. Hence f(n) = 3f(n-1) when n > 1.

Thus, the recursive function is

f(1) = 8

f(n) = 3 f(n-1) if n > 1.

Option D is the correct answer.

Step-by-step explanation: