Determine the common ratio and use it to write the explicit rule

Question

Determine the common ratio and use it to write the explicit rule.

1. 64,16,4,1,0.25- what is the common ratio??
2. what is the zero term (a) ?
3. what is the explicit rule using a_n=

Answer 1

each term is 1/4 of the previous term, so common ratio is 1/4

zero term (a) is 64

explicit rule is an = a * r ^ (n-1) =

an = 64 * (1/4)^(n-1)