Need some help evaluating a limit

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In summary, the conversation discusses a problem about improper integrals, specifically \lim_{t→∞}\frac{sin (t)}{\sqrt{t}}. The participants explore different approaches to solving the problem, including L'Hopital's rule and the squeeze theorem. They also discuss the maximum and minimum values of sin(t) and the relevance of the ε-δ definition. Finally, the original problem is presented as \int^{π}_{0}\frac{dt}{\sqrt{t}+sin(t)}.
  • #1
Bipolarity
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Homework Statement



[tex] \lim_{t→∞}\frac{sin (t)}{\sqrt{t}} [/tex]

Homework Equations


The Attempt at a Solution


This was actually part of a larger problem about improper integrals. The problem has been reduced to this, but I have no idea how to proceed from here. I know that sin(x) behaves very bizarrely at infinity, so I don't know if L'Hopital's rule can even be applied here.

My intuition tells me that the answer is 0, but how can we prove this? Must we refer to the ε-δ definition?

BiP
 
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  • #2
What are the maximum and minimum possible values that sin(t) can ever achieve?
 
  • #3
Bipolarity said:

Homework Statement



[tex] \lim_{t→∞}\frac{sin (t)}{\sqrt{t}} [/tex]

Homework Equations



The Attempt at a Solution


This was actually part of a larger problem about improper integrals. The problem has been reduced to this, but I have no idea how to proceed from here. I know that sin(x) behaves very bizarrely at infinity, so I don't know if L'Hopital's rule can even be applied here.

My intuition tells me that the answer is 0, but how can we prove this? Must we refer to the ε-δ definition?

BiP
Use the squeeze theorem.

What's [itex] \lim_{t→∞}\ 1/\sqrt{t}\ ?[/itex]

How about giving us the entire problem?
 
  • #4
Are you familiar with the squeeze theorem?
 
  • #5
Ah, good old squeeze theorem why didn't I think of that?

Thanks guys!

BiP
 
  • #6
The original problem (for Sammy):

[tex] \int^{π}_{0}\frac{dt}{\sqrt{t}+sin(t)} [/tex]

BiP
 

What is a limit?

A limit is a mathematical concept that represents the value that a function approaches as its input approaches a certain value or point. It is often used to describe the behavior of a function near a specific point.

How do you evaluate a limit?

To evaluate a limit, you can either use algebraic techniques or graphing techniques. Algebraically, you can use substitution or factoring to simplify the expression and then plug in the value the function is approaching. Graphically, you can plot the function and observe the behavior near the point of interest.

What is the difference between a one-sided limit and a two-sided limit?

A one-sided limit only considers the behavior of the function as the input approaches the point from one direction, either the left or the right. A two-sided limit considers the behavior of the function as the input approaches the point from both the left and the right sides.

What is a limit at infinity?

A limit at infinity is a type of limit that describes the behavior of a function as the input approaches positive or negative infinity. It can help determine the long-term behavior of a function.

Why are limits important in calculus?

Limits are important in calculus because they help us understand the behavior of functions and analyze how they change over time or approach certain values. They are also essential in finding derivatives and integrals, which are fundamental concepts in calculus.

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