1. ## geometric Sequence

(b) Consider the following geometric sequence.
400
,
320
,
256
,
204
.8,
...
(i)
Write down a recurrence system that describes this sequence.
(Denote the sequence by
xn,and itsfirsttermby x1.)
[
2]
(ii) Find a closed form for this sequence.
[
2]
(iii) Use the closed form from part (b)(ii) to find the tenth term of the
[
2]

2. note 320/400=0.8 (=256/320=...). You thus find x_n = 0.8 x_(n-1), the closed form is then given by x_n = 400*(0.8)^(n-1).
Can you do the other exercise yourself now?

3. Originally Posted by batman
note 320/400=0.8 (=256/320=...). You thus find x_n = 0.8 x_(n-1), the closed form is then given by x_n = 400*(0.8)^(n-1).
Can you do the other exercise yourself now?
Im not sure i understand the 320/400 part but am not sure of the formula you have given.