Another one is this one that I am unsure how to go about it:
Find the nth term of the geometric series: 1024, 512, 256, 128,...
an = a1 *r^(n-1) --------------***
1024, 512, 256, 128,...
So, a1 = 1024.
r = 512/1024 = 1/2
r = 256/512 = 1/2
r = 128/256 = 1/2
Hence, nth term is
an = a1 *r^(n-1)
an = 1024 *(1/2)^(n-1)
an = 1024 *[(1/2)^n / (1/2)]
an = 1024 *[2 *(1/2)^n]
an = 2048 *[1^n / 2^n]
an = 2048 *[1 / 2^n]
an = 2048 / 2^n ----------------answer.
Check,
a3 = 256 --------given
256 =? 2048 / (2^3)
256 =? 2048 / 8
256 =? 256
Yes, so, OK.
Hello, Mike!
If you have the formula and can recognize the parts, you're all set.Find the nth term of the geometric series: 1024, 512, 256, 128, ...
The nth term of a geometric series: a_n .= .ar^{n-1}
We can see that the first term is: a = 1024, right?
And we should be able figure out that: r = 1/2
Then we plug them into the formula . . .
So where exactly is your difficulty?