What is the Limit of the Sequence {[(n+3)/(n+1)]^n} as n Approaches Infinity?

Click For Summary
SUMMARY

The limit of the sequence {[(n+3)/(n+1)]^n} as n approaches infinity is e^2. To derive this, one must manipulate the fraction inside the parentheses using long division to express it in the form of (1 + 1/t)^t, which aligns with the definition of the mathematical constant e. The discussion clarifies that the entire fraction is raised to the nth power, not just the denominator, which is crucial for accurate calculation.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with the definition of the mathematical constant e
  • Basic algebraic manipulation skills, including long division
  • Knowledge of sequences versus series in mathematics
NEXT STEPS
  • Study the properties of limits and sequences in calculus
  • Learn about the derivation and applications of the constant e
  • Practice long division techniques for algebraic expressions
  • Explore the differences between sequences and series in mathematical analysis
USEFUL FOR

Students of calculus, mathematics educators, and anyone interested in understanding limits and sequences in advanced mathematics.

Beamsbox
Messages
61
Reaction score
0
Basically,

find the limit of the sequence:

{[(n+3)/(n+1)]^n}, from n=1 to infinity

Book says it's supposed to be e^2, and indeed the graph shows that... I'm not sure what to do with the top of the fraction. Working with the bottom and dividing by n, I obtain, lim as n approaches infinity, (1+(1/n))^n, which is the definition of e... but I'm not sure of the legality of dividing the top and bottom by n, as they're inside the parenthesis to begin with... but if I do it to the top too, I get lim (1+3/n)^n, which I'm not sure what to do with...
lost...

Any help much appreciated!
 
Last edited:
Physics news on Phys.org
Your title is wrong; this isn't an infinite series, it is a sequence. And although it isn't written that way, I assume it is the whole fraction that is raised to the nth power, not just the denominator.

Hint: Do long division on the fraction on the inside to write it as 1 + (..) and try to get it in the form

(1 + 1/t)t.
 
Right, nice assumption, edited and fixed. Long division, I knew I needed it in the form ofthe definition of e, but didn't know how... I'll check it out. Thanks for the help.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 20 ·
Replies
20
Views
2K
Replies
2
Views
1K
Replies
17
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K