Question

Write an

explicit formula for
an,
then
th
term of the sequence 100, 20, 4, ....

Answer 1

Explanation:

a1 = 100

r = 1/5

an = 100 (1/5)^(n - 1)

Try it. We have the answer for a_3

a_3 = 100 * (1/5)^(3 - 1)

a_3 = 100 * (1/5)^2

a_3 = 100 * 1/25

a_3 = 4 which is just what the series says should be the answer.