Question

Which choice is the explicit formula for the following geometric sequence: 0.5, -0.1, 0.02, -0.004, 0.0008?

a. an = -0.5(0.3)^(n-1)
b. an = 0.5(-0.2)(-1)
c. an = -0.5(0.2)(n-1)
d. an = -0.5(-0.2)^(n-1)

Answer 1

The explicit formula for the given geometric sequence is an = 0.5 * (-0.2)^(n-1).

Step-by-step explanation:

The explicit formula for a geometric sequence can be written as an = a * r^(n-1), where 'a' is the first term and 'r' is the common ratio. In this case, the first term is 0.5 and the common ratio is -0.2.

So, the explicit formula for the given sequence is an = 0.5 * (-0.2)^(n-1).