Can You Help Me Compute These Limits as X Approaches Infinity?

In summary, to compute the limit of (1+2/x)^x or (1-1/x)^x and (1+1/x)^(x+3) when x approaches infinity, we can use the substitution x/2=y for the first problem and y=x-1 for the third problem. This leads to the conclusion that all three limits are equivalent to lim (1+1/x)^x as x approaches infinity, which is equal to e. Therefore, the correlation between the limits is that they all approach the value of e.
  • #1
MathematicalPhysicist
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i need to compute the lim of (1+2/x)^x or (1-1/x)^x and (1+1/x)^(x+3) when x approaches infinity.
if you can provide a steady method to compute it, it will be appreciated.

btw i know that lim (1+1/x)^x as x->inf is "e", but does it have any correlation to here.
 
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  • #2
loop quantum gravity said:
i need to compute the lim of (1+2/x)^x or (1-1/x)^x and (1+1/x)^(x+3) when x approaches infinity.
if you can provide a steady method to compute it, it will be appreciated.
btw i know that lim (1+1/x)^x as x->inf is "e", but does it have any correlation to here.
Yes, it does.
For the first problem, replace x/2=y. You should determine lim (1+1/y)^(2y) as y->infinity.
lim (1+1/y)^(2y)=lim ((1+1/y)^2)->
(lim (1+1/y))^2 = e^2 if y->infinity. But this is equivalent with the original limit when x -> infinity.
As for the second problem, (1+1/x)^(x+3)=((1+1/x)^x)*(1+1/x)^3. You can proceed from here.
In case of the third problem
1-1/x=1/[1+1/(x-1)]
Let be y= x-1. If x -> infinity , so does y.
You have to detemine the limit
lim (1-1/x)^x when x->infinity. It is equivalent with
lim[(1/(1+1/y)]^(y+1)) when y->infinity.
lim[(1/(1+1/y)]^(y+1))=
1/lim[(1+1/y)^(y+1)]=1/lim[(1+1/y)^y*(1+1/y)] =1/[lim(1+1/y)^y*lim(1+1/y)]=1/e
ehild
 
  • #3
arrange and factorize
 
  • #4
thanks, i think it's a simple substitution.
 

1. What does it mean for X to approach infinity?

When we say X approaches infinity, we mean that the value of X is getting larger and larger without any bound. In other words, we are looking at the behavior of the function as the input value gets closer and closer to infinity.

2. How do I compute a limit as X approaches infinity?

To compute a limit as X approaches infinity, we use the concept of limits in calculus. This involves evaluating the limit of the function as X gets closer and closer to infinity. We can use algebraic manipulation, graphing, or other mathematical techniques to determine the limit.

3. Do all functions have a limit as X approaches infinity?

No, not all functions have a limit as X approaches infinity. Some functions may have a limit, while others may not. It depends on the behavior of the function as X gets closer to infinity. For example, a linear function will have a limit, but a sinusoidal function may not.

4. What is the significance of computing limits as X approaches infinity?

Computing limits as X approaches infinity allows us to understand the behavior of a function at extremely large values. It helps us determine if the function approaches a specific value, grows without bound, or oscillates between values as X gets larger. This information is useful in many real-world applications and in understanding the overall behavior of a function.

5. Can I use L'Hopital's rule to compute limits as X approaches infinity?

Yes, L'Hopital's rule can be applied to compute limits as X approaches infinity. This rule states that if the limit of a function is in an indeterminate form (such as 0/0 or ∞/∞), then the limit of the derivative of the function over the derivative of the input variable will be equivalent. This rule can be useful in simplifying and evaluating complex limits as X approaches infinity.

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