Question

What is an explicit formula for the geometric sequence 64,16,4,1,... where the first term

should be f(1)
[Choose two answers]

A. f(n)=64(1/4)n-1
B. f(n)=16(1/4)n-1
C. f(n)=64(1/4)n
D. f(n)=16(1/4)n-2

Answer 1

A

Explanation:

The explicit formula for a geometric sequence is

f(n) = f(1)
`(r)^(n-1)`

where f(1) is the first term and r the common ratio

Here f(1) = 64 and r =
`(f(2))/(f(1))` =
`(16)/(64)` =
`(1)/(4)` , then

f(n) = 64
`((1)/(4)) ^(n-1)` → A