Question

A recursive rule for a geometric sequence is a1=49;an=3an−1 . What is the explicit rule for this sequence? Enter your answer in the box. an=

Answer 1

Answer:

an= 4/9(3^n-1)

Step-by-step explanation:

Just took the test and passed with this answer. For future students looking. I am 100% correct on this. :)

Answer 2

Answer :

Explicit rule is

$a_n=49(3)^{n-1}$

Step-by-step explanation:

A recursive rule for a geometric sequence is a1=49;an=3an−1

First term a1= 49

$a_2= 3 * a_1= 3*49= 147$

$a_2= 3 * a_2= 3*147= 441$

To get second term, multiply the first term by 3

So common ratio = 3

Explicit rule for geometric sequence is

$a_n=a_1(r)^{n-1}$

Where a1 is the first term

r is the common ratio

a1= 49  and r= 3

$a_n=49(3)^{n-1}$