Can the limit of (x,y) at (1,0) be found using l'hopital's rule?

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In summary, the conversation discusses finding the limit of a function ((x-y-1)^2/(x+y-1)^2) as (x,y) approaches (1,0). The person has attempted to use l'hopital's rule but has not been successful. They are then given a hint to approach the limit along different paths to determine if it exists.
  • #1
brunette15
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I am trying to find the limit of the following:

lim(x,y)--> (1,0) ((x-y-1)2/(x+y-1)2)

I have had a few attempts trying to use l'hopital's rule but i don't seem to be getting anywhere...
 
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  • #2
brunette15 said:
I am trying to find the limit of the following:

lim(x,y)--> (1,0) ((x-y-1)2/(x+y-1)2)

I have had a few attempts trying to use l'hopital's rule but i don't seem to be getting anywhere...
For this you need to show that the limit exists (and is the same) along all paths approaching it.

Hint: Approach the limit point along the line y = x - 1 and the line y = -x + 1. Is the limit the same in both cases?

-Dan
 

1. What is the definition of a limit?

A limit is a mathematical concept that represents the value that a function approaches as the input approaches a certain value. It is denoted as the notation lim x→a f(x) and can also be thought of as the output of a function when the input is extremely close to a specific value.

2. How do I calculate the limit of a function?

To calculate a limit, you can use algebraic methods such as factoring, simplifying, or expanding the function. You can also use graphical methods like looking at the behavior of the function on a graph. Another way to calculate a limit is by using numerical methods such as plugging in values that are extremely close to the limit value. In some cases, you may need to use more advanced techniques such as L'Hôpital's rule or the squeeze theorem.

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

A one-sided limit only considers the behavior of the function from one side of the limit value, either from the left or the right. This is denoted as lim x→a- f(x) or lim x→a+ f(x). On the other hand, a two-sided limit considers the behavior of the function from both sides of the limit value and is denoted as lim x→a f(x).

4. Can a limit not exist?

Yes, a limit can fail to exist for several reasons. One common reason is when the left and right-hand limits approach different values. This is known as a jump discontinuity. Another reason is when the function approaches infinity, either positive or negative. A limit can also fail to exist if the function oscillates indefinitely as the input approaches the limit value.

5. How can calculating limits be useful in real-world applications?

Calculating limits can be useful in real-world applications such as determining the maximum and minimum values of a function, finding the velocity and acceleration of an object, or predicting the behavior of a system. It can also be used in economics, physics, and engineering to model and analyze various systems and processes.

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