How to Simplify a Complicated Limit

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In summary, the conversation is about evaluating a limit involving a Laplace transform. The person has been trying to use L'Hopital's rule to solve it but it has become more complicated. They ask if there is a quicker way to solve the problem. The expert suggests simplifying the expression by dropping certain terms that approach zero or are dominated by other terms. This will make it easier to use l'Hopital's rule and should lead to a simpler solution.
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Bipolarity
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Homework Statement


Been trying to evaluate this rather annoying limit for the past few minutes.

[tex] \lim_{t→∞}\frac{t-\frac{1}{ln(t)}}{(ln(t))e^{at-\frac{t}{ln(t))}}} [/tex]


Homework Equations





The Attempt at a Solution


I tried L'Hopital's rule but it seems to become only more messy. I was curious if there was any "quick" way to this problem? It's been a while since I took calculus, and I'm using this as part of a Laplace transform I'm trying to do.

BiP
 
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  • #2
Bipolarity said:

Homework Statement


Been trying to evaluate this rather annoying limit for the past few minutes.

[tex] \lim_{t→∞}\frac{t-\frac{1}{ln(t)}}{(ln(t))e^{at-\frac{t}{ln(t))}}} [/tex]

Homework Equations


The Attempt at a Solution


I tried L'Hopital's rule but it seems to become only more messy. I was curious if there was any "quick" way to this problem? It's been a while since I took calculus, and I'm using this as part of a Laplace transform I'm trying to do.

BiP

Try and simplify it first. Drop terms that aren't important. In the numerator 1/ln(t) approaches 0, t approaches infinity. So you can drop the 1/ln(t) without affecting the limit. In the denominator, if a>0, then t/ln(t) in the exponent goes to infinity, but it is dominated by at going to infinity faster (to see this check that the ratio (t/ln(t))/(at) goes to zero), so drop that. That should give you something easier to do l'Hopital from. As you do l'Hopital, keep checking for terms that grow more slowly than others and keep simplifying.
 

FAQ: How to Simplify a Complicated Limit

1. What is a complicated limit?

A complicated limit is a type of mathematical concept that deals with the behavior of a function as its input approaches a certain value. It is considered "complicated" when the function is not easily evaluated or does not have a straightforward solution.

2. How is a complicated limit different from a regular limit?

A regular limit is a limit that can be easily evaluated using algebraic techniques. A complicated limit, on the other hand, may require more advanced mathematical methods such as L'Hôpital's rule or series expansions to solve.

3. What are some common examples of complicated limits?

Some common examples of complicated limits include limits involving trigonometric functions, logarithmic functions, and functions with asymptotes. These types of functions often have complex behaviors near certain input values, making their limits more difficult to determine.

4. How do scientists use complicated limits in their research?

Scientists use complicated limits in various fields of study, such as physics, engineering, and economics. These limits help them model and analyze real-world phenomena, such as the behavior of particles in a physical system or the growth of a population over time.

5. How can I solve a complicated limit?

To solve a complicated limit, you may need to use advanced mathematical techniques or consult tables or software for series expansions or other formulas. It is also helpful to have a solid understanding of algebra and calculus to understand the behavior of the function and its limit.

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