How Do You Find the Limit of the Series S_n = \dfrac {3}{8}⋅\dfrac {4^n}{3^n}?

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The series S_n = (3/8) * (4^n / 3^n) was analyzed to find its limit, with initial calculations suggesting divergence to infinity. The discussion highlights the importance of verifying the formula against multiple terms in the series rather than just the first few. A correction was made, indicating that the series could also be expressed as S_n = n / (1 + n), which converges to 1 as n approaches infinity. The conversation emphasizes the need for careful examination of series representations to ensure accurate conclusions. Ultimately, the limit of the original series was deemed incorrect without proper validation.
chwala
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Homework Statement
See attached.
Relevant Equations
Limits
Consider the series below;

1644709958718.png


From my own calculations, i noted that this series can also be written as ##S_n##=##\dfrac {3}{8}##⋅##\dfrac {4^n}{3^n}##. If indeed that is the case then how do we find the limit of my series to realize the required solution of ##1## as indicated on the textbook? I tried taking limits...L Hopital's rule... and still got ##∞## implying divergence. Are we required to solely maintain the series in the pattern indicated on the text and not any other way?

In other words, if one was given a specific question to find the limit of my series ##S_n##=##\dfrac {3}{8}##⋅##\dfrac {4^n}{3^n}##in an exam, then would it be correct to state ##∞##?
 
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Your formula is wrong. You probably fit it to the first two values, and didn't check if it matches anything else.
 
Office_Shredder said:
Your formula is wrong. You probably fit it to the first two values, and didn't check if it matches anything else.
True it is wrong...i ought to have checked if it applies to the sequence ##S_3##...but we could also have
...our series ##\dfrac {1}{2}##, ##\dfrac {2}{3}##, ##\dfrac {3}{4}##,##\dfrac {4}{5},##... as
##S_n##=##\dfrac {n}{1+n}##
Cheers :cool:
 
Last edited:

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