Question

Which of the following is the formula for the geometric sequence?
320, 80, 20, 5,...
A. an = 320(1/4)n-1
B. an = 320(4)n-1
C. an = 4(320)n-1

Answer 1

Do you have a guess as to which one you think is correct?

Answer 2

It would not hurt to plug in a few values into each function. :P

Answer 3

b?

Answer 4

If geometric,
r=80/320=1/4
a=320
formula gives \[\huge T_n=ar^{n-1}\]
\[\huge T_n=320(1/4)^{n-1}\]

Answer 5

thankyou!!!:)