Asked by Max

Calculate the missing terms of the geometric sequence ..., 2048, ?, ?, ?, 8, ... Select all that apply.

1,538, 1,028, 518 *****
1,534, 1,020, 514
512, 128, 32
-512, 128, -32
-1,534, 1,020, -514
-1,538, 1,028, -518

I have to pick 2 options. I know the first one is correct, but I don't know how to get another option. Please help? Thanks
Answered by bobpursley
you are given a2, a6.

a6=8=2048r^4
r^4=8/2048=
r=+-1/4
2048,<b>512,128,32,</b>8,2....
or r could be -1/4
2048,<b>-512,128,-32,</b>8,-2....
so two answers are right.
r=
2048*1/251=
Answered by Max
That's interesting, I was super wrong 0_0 I guess its the middle two...
Wait, is this because this is geometric and not arithmetic? Because I got answer a through adding and doing the mean thing... is that where I went wrong?
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