SOLUTION: Is this correct? Use the geometric sequence of numbers 1, 1/2, 1/4, 1/8,…to find the following: What is r, the ratio between 2 consecutive terms? Answer: r = (1/2)/1 = 1/2

Algebra.Com
Question 83996: Is this correct?
Use the geometric sequence of numbers 1, 1/2, 1/4, 1/8,…to find the following:
What is r, the ratio between 2 consecutive terms?
Answer: r = (1/2)/1 = 1/2
Show work in this space.
Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 10 terms? Please round your answer to 4 decimals.
Answer:
Show work in this space.
S(n) = a(1)[r ^(n + 1) – 1)/(r – 1)
S(10) = 1[(1/2) ^ 9 – 1] / [(1/2)-1]
S(10) = [-0.998046875…] / [-0.5] = 1.99609375…
Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 12 terms? Please round your answer to 4 decimals.
Answer:
Show work in this space.
S(n) = a(1)[r ^(n + 1) – 1)/(r – 1)
S(12) = 1[(1/2) ^ 9 – 1] / [(1/2)-1]
S(12) = [-0.998046875…] / [-0.5] = 1.99609375…
n = 12

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!

The ratio r is the factor to get from term to term. So
r=nth term/(n-1) term


The sequence is cut in half each term, so the sequence is


The sum of a geometric series is
where a=1
So plug in n=10 to find the sum of the first 10 partial sums


So the sum of the first ten terms is or 1.99805 approximately

Use the same formula to find the sum of the 1st 12 terms
where a=1
So plug in n=12 to find the sum of the first 12 partial sums


So the sum of the first twelve terms is or 1.99951 approximately


RELATED QUESTIONS

Use the geometric sequence of numbers 1, 2, 4, 8,…to find the following What is r, the... (answered by Earlsdon)
Use the geometric sequence of numbers 1, 2, 4, 8,…to find the following: What is r,... (answered by jim_thompson5910)
the geometric sequence of numbers 1, 1/2, 1/4, 1/8,…to find the following: What is r,... (answered by jim_thompson5910)
Use the geometric sequence of numbers 1, 2, 4, 8,…to find the following: a)What is r,... (answered by sarah_adam)
Use the geometric sequence of numbers 1, 2, 4, 8,... to find the following: a) What is (answered by Edwin McCravy)
Use the geometric sequence of numbers 1, 2, 4, 8,… to find the following: What is r, (answered by jim_thompson5910)
Use the geometric sequence of numbers 1, 1/2, 1/4, 1/8,…to find the following: a)What is (answered by stanbon)
2) Use the geometric sequence of numbers 1, 2, 4, 8,…to find the following: a) What is (answered by jim_thompson5910)
2) Use the geometric sequence of numbers 1, 2, 4, 8,…to find the following: a) What is (answered by jim_thompson5910)
Use the geometric sequence of numbers 1, 2, 4, 8,…to find the following: a) What is r,... (answered by venugopalramana)