| 
 
 
| Question 39011:  Don't know how to do these. Please help.
 3)	Use the geometric sequence of numbers 1, 1/3, 1/9 , 1/27… to find the following:
 a)	What is r, the ratio between 2 consecutive terms?
 Answer:
 Show work in this space.
 
 
 
 b)	Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 10 terms? Carry all calculations to 7 significant figures.
 Answer:
 Show work in this space.
 
 
 
 c)	Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 12 terms? Carry all calculations to 7 significant figures.
 Answer:
 Show work in this space.
 
 
 
 d)	What observation can make about these sums? In particular, what number does it appear that the sum will always be smaller than?
 Answer:
 
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! 3) Use the geometric sequence of numbers 1, 1/3, 1/9 , 1/27… to find the following: a) What is r, the ratio between 2 consecutive terms?
 Answer:
 Show work in this space.
 r = [1/3]/1= 1/3
 b) Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 10 terms? Carry all calculations to 7 significant figures.
 Answer:
 Show work in this space.
 S(10)=[r^10-1]/[r-1]= [(1/3)^10-1]/[1/3 - 1]
 =-0.99998306.../(-2/3)1.49997460...
 
 
 c) Using the formula for the sum of the first n terms of a geometric series, what is the sum of the first 12 terms? Carry all calculations to 7 significant figures.
 Answer:
 Show work in this space.
 S(12)=[(1/3)^12 - 1]/[(1/3)-1]= -0.99999812.../(-2/3)
 =1.49999718...
 
 
 d) What observation can you make about these sums? In particular, what number does it appear that the sum will always be smaller than?
 Answer:
 I'll leave this to you.
 Cheers,
 Stan H.
 
 | 
  
 | 
 |