Question

Part B What is the recursive formula for the sequence 8, 10, 12.5, 15.625

Answer 1

Explanation:

The given sequence can be written as:

a_1 = 8

a_2 = 10

a_3 = 12.5

a_4 = 15.625

To find the recursive formula, we need to find the common ratio (r) between consecutive terms:

r = a_2 / a_1 = 10 / 8 = 1.25

r = a_3 / a_2 = 12.5 / 10 = 1.25

r = a_4 / a_3 = 15.625 / 12.5 = 1.25

Since the common ratio is constant, we can use the formula for a geometric sequence to find the recursive formula:

a_n = r * a_{n-1}

Substituting r = 1.25 and a_1 = 8, we get:

a_n = 1.25 * a_{n-1}

Therefore, the recursive formula for the given sequence is:

a_n = 1.25 * a_{n-1}, with a_1 = 8.