Does the Limit Exist? Check to Find Out!

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In summary, the conversation involves discussing the limit of a function using De L'Hoptal's Rule. The initial limit is found to be $-\frac{4}{3}$ and the question is raised about how to check the limit for a different trajectory. The conversation ends with considering different trajectories and the need for further analysis.
  • #1
mathmari
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Hey! :eek:

I have found applying De L'Hoptal's Rule that $$\lim_{x \rightarrow 0} \frac{\sin 2x-2x}{x^3}=-\frac{4}{3}$$

Now I am asked whether the limit $$\lim_{(x, y) \rightarrow (0, 0)} \frac{\sin 2x-2x+y}{x^3+y}$$ or not.

How could we check that ?? (Wondering)
 
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  • #2
mathmari said:
Hey! :eek:

I have found applying De L'Hoptal's Rule that $$\lim_{x \rightarrow 0} \frac{\sin 2x-2x}{x^3}=-\frac{4}{3}$$

Now I am asked whether the limit $$\lim_{(x, y) \rightarrow (0, 0)} \frac{\sin 2x-2x+y}{x^3+y}$$ or not.

How could we check that ?? (Wondering)

Hi! (Wave)

I would start with checking what the limit is on different lines, say $y=0$ respectively $x=0$. (Thinking)
 
  • #3
mathmari said:
Hey! :eek:

I have found applying De L'Hoptal's Rule that $$\lim_{x \rightarrow 0} \frac{\sin 2x-2x}{x^3}=-\frac{4}{3}$$

Now I am asked whether the limit $$\lim_{(x, y) \rightarrow (0, 0)} \frac{\sin 2x-2x+y}{x^3+y}$$ or not.

How could we check that ?? (Wondering)

If $(x,y) \rightarrow (0,0)$ along the trajectory y=0 the limit is $- \frac{4}{3}$ as You have found... if $(x,y) \rightarrow (0,0)$ along the trajectory $y = 2\ x - \sin 2x$ the limit is 0... what do You can conclude?...

Kind regards

$\chi$ $\sigma$
 

Related to Does the Limit Exist? Check to Find Out!

1. What is the concept of "limit" in mathematics?

The concept of limit in mathematics refers to the value that a function or sequence approaches as the input or index approaches a certain value. It is used to describe the behavior of a function or sequence near a specific point or at infinity.

2. How is the limit of a function calculated?

The limit of a function is calculated by evaluating the function at various points near the point in question and observing the trend of the values. If the values approach a specific number as the points get closer to the point in question, then that number is considered to be the limit.

3. Can a function have more than one limit?

No, a function can only have one limit at a point. If the function has different limits as the input approaches a certain value from different directions, then the limit does not exist.

4. How does the concept of limit apply to real-life situations?

The concept of limit can be applied to real-life situations such as calculating the speed of an object at a specific point in time or finding the average rate of change in a process. It is also used in fields such as economics, physics, and engineering to model and analyze various phenomena.

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

A one-sided limit only considers the values of a function as the input approaches a certain value from one side, either from the left or the right. A two-sided limit, on the other hand, considers the values from both sides and determines if they approach the same value. This is important in determining if a limit exists or not.

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