Question

geometric seqence

Answer 1

Find the sum of the geometric sequence.

three divided by two, three divided by eight, three divided by thirty two, three divided by one hundred and twenty eight, three divided by five hundred and twelve

Answer 2

Sum of geometric sequence is \[S_{n} = \frac{ 1-r^{n} }{ 1-r } \]
if r < 1 where r is common ratio of two conjugate terms.
If r > 1 then we have \[S_{n} = \frac{ r ^{n} - 1 }{ r - 1 }\]

Answer 3

wait whats r?

Answer 4

Here we have the common ratio is 1/4 which is less than 1
so we get \[Sn = \frac{ 1-(1/4)^{5} }{ 1 - 1/4 }\]
which gives you \[Sn = \frac{ 1 - 1/1024 }{ 3/4 }\]

Answer 5

so 3/4 has to have a denominator that equals 1024?

Answer 6

No that now equal 1 - 1/1024 is numerator and 3/4 is denominator.

Answer 7

I hope this will help you.

Answer 8

no :c cuz my answers are 1/256, 1/16, 1023/512, or 341

Answer 9

So (341/256)/(3/4) = 341/256

Answer 10

wait.... thats still not an answer thats like 2 different answers .-.

Answer 11

http://www.wolframalpha.com/input/?i=3%2F2%2B3%2F8%2B3%2F32%2B3%2F128%2B3%2F512

Answer 12

@shindekrishna put \(a = \dfrac{3}{2}\), formula gives the correct answer...

Answer 13

\(\large S_{n} = a\left(\frac{ 1-r^{n} }{ 1-r }\right) \)

Answer 14

okay so \[\frac{ 1 }{ 4 } (\frac{ 1-\frac{ 1 }{ 4 }^5 }{ 1-\frac{ 1 }{ 4 } })\]
that is alot of math

Answer 15

@Luigi0210

Answer 16

Sorry, can't help atm.

Answer 17

okaay thanks you anyways c: