Use the recursively defined geometric sequence a1 = 5/6, a n = 4a n-1 and find the common ratio.
A. 4
B. -2/3
C. 5/6
D. 10/3
To find the common ratio of a geometric sequence, we divide any term by the previous term. According to the recursive definition, the n-th term a_n is given by a_n = 4a_(n-1).
Let's find the common ratio by dividing the n-th term a_n by the previous term a_(n-1):
a_n / a_(n-1) = (4a_(n-1)) / a_(n-1) = 4
Therefore, the common ratio is 4.
So, the correct answer is A. 4.