Using L'Hospital's Rule to Find the Limit of (1+1/n)^n as n Approaches Infinity

  • Thread starter Thread starter astrololo
  • Start date Start date
  • Tags Tags
    Limit
Click For Summary
SUMMARY

The limit of (1 + 1/n)^n as n approaches infinity can be evaluated using L'Hospital's Rule. The correct approach involves setting y = (1 + 1/n)^n and taking the natural logarithm, resulting in ln y = n ln(1 + 1/n). This expression can be rewritten as ln(1 + 1/n)/(1/n), allowing for the application of L'Hospital's Rule. The limit then simplifies to e, confirming that lim (1 + 1/n)^n = e as n approaches infinity.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with L'Hospital's Rule
  • Knowledge of natural logarithms
  • Basic algebraic manipulation skills
NEXT STEPS
  • Study the application of L'Hospital's Rule in various limit problems
  • Learn about the properties of exponential functions
  • Explore the concept of continuity and limits in calculus
  • Investigate the derivation of the number e and its significance in mathematics
USEFUL FOR

Students studying calculus, particularly those learning about limits and exponential functions, as well as educators looking for effective teaching strategies for these concepts.

astrololo
Messages
200
Reaction score
3

Homework Statement


I have lim of n > infinity (1+1/n)^n

Homework Equations

The Attempt at a Solution


I know that I must use l'hospital rule and setting ln y = n ln (1+1/n)

And after lim n ln (1+1/n) as n approaches infinity.

After what do I do ?
 
Physics news on Phys.org
astrololo said:

Homework Statement


I have lim of n > infinity (1+1/n)^n

Homework Equations

The Attempt at a Solution


I know that I must use l'hospital rule and setting ln y = n ln (1+1/n)

And after lim n ln (1+1/n) as n approaches infinity.

After what do I do ?

Try writing it as$$\frac{\ln(1 + \frac 1 n)}{\frac 1 n}$$before using L'Hospital's rule and taking the limit.
 
  • Like
Likes   Reactions: Student100
LCKurtz said:
Try writing it as$$\frac{\ln(1 + \frac 1 n)}{\frac 1 n}$$before using L'Hospital's rule and taking the limit.
OK but I'll have to take the natural logarithm right ?
 
astrololo said:
OK but I'll have to take the natural logarithm right ?
Didn't you already take the logarithm to get that expression?
 
astrololo said:

Homework Statement


I have lim of n > infinity (1+1/n)^n

Homework Equations

The Attempt at a Solution


I know that I must use l'hospital rule and setting ln y = n ln (1+1/n)

And after lim n ln (1+1/n) as n approaches infinity.

After what do I do ?

You've either applied LH incorrectly, or I'm misreading you. How did you apply LH (how did you set it up) when you're at the step: $$exp[\lim_{n\to\infty}(n\log(1+\frac{1}{n})] $$

Never mind, didn't see the new post update. :) Ignore me LC's already said the same thing.
 
Student100 said:
You've either applied LH incorrectly, or I'm misreading you. How did you apply LH (how did you set it up) when you're at the step: $$exp[\lim_{n\to\infty}(n\log(1+\frac{1}{n})] $$

Never mind, didn't see the new post update. :) Ignore me LC's already said the same thing.
Wait, what I just wrote was correct or not ? Am I in the right direction ?
 
astrololo said:
Wait, what I just wrote was correct or not ? Am I in the right direction ?

Follow post #2.
 
astrololo said:

Homework Statement


I have lim of n > infinity (1+1/n)^n

Homework Equations

The Attempt at a Solution


I know that I must use l'hospital rule and setting ln y = n ln (1+1/n)

And after lim n ln (1+1/n) as n approaches infinity.

After what do I do ?
For this to work out correctly, you need to keep track of your equations. Each line you write should be an equation.
Let ##y = (1 + 1/n)^n##
##\ln y = n \ln(1 + 1/n) = \frac{\ln(1 + 1/n)}{1/n}##
Now take limits of both sides, after which you can apply L'Hopital's Rule.

Again, take care to work with equations at each step.
 
Mark44 said:
For this to work out correctly, you need to keep track of your equations. Each line you write should be an equation.
Let ##y = (1 + 1/n)^n##
##\ln y = n \ln(1 + 1/n) = \frac{\ln(1 + 1/n)}{1/n}##
Now take limits of both sides, after which you can apply L'Hopital's Rule.

Again, take care to work with equations at each step.
I'm sorry if it takes time to respond, I have like several question to answer at the same and I must give this tomorrow lol Don't worry, I keep track of what I write on paper. I'll respond here if something I'm having a problem with.
 
  • #10
Ok thanks it worked
 
  • #11
astrololo said:
I'm sorry if it takes time to respond, I have like several question to answer at the same and I must give this tomorrow lol Don't worry, I keep track of what I write on paper. I'll respond here if something I'm having a problem with.

Yes, but it is extremely rude and time consuming for the people on this site. How are we to know the work you present means.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
Replies
17
Views
2K
Replies
6
Views
2K
  • · Replies 23 ·
Replies
23
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
Replies
15
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 8 ·
Replies
8
Views
1K
Replies
17
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K