In: Advanced Math
For the following exercises, write a recursive formula for each geometric sequence.
an = {0.61, 1.83, 5.49, 16.47, ...}
Consider the following geometric sequence:
{0.61, 1.83, 5.49, 16.47,…| ...... (1)
The first term of above sequence is a1 = 0.61.
Common ratio of the above sequence will be obtained by dividing its second term by the first term,
r = a2 ÷ a1
= 1.83 + 0.61
= 3
The recursive formula for a geometric sequence,
an = ran-1, for n ≥ 2
Substitute r = 3, the recursive formula for the nth term of the geometric sequence will be,
an = 3an-1, for n ≥ 2
Therefore, the recursive formula for the above geometric sequence is,
a1 = 0.61
an = 3an-1, for n ≥ 2.