Evaluating Multivariable Limit: (x^2+y^2)/(1+y^2)

In summary, the conversation discusses evaluating the limit of (x^2+y^2)/(1+y^2) as (x,y) approaches (0,0) and determining whether it exists or not. Some participants believe the limit does not exist while others argue that it does exist due to the continuity of the function. Further clarification is requested on the method of evaluation.
  • #1
marquitos
9
0
Multivariable Limits!

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

evaluate the limit or determine that it does not exist.
Im pretty sure that the limit does not exist because if i take it from the y and x axises the values don't match up but not really sure if that is the right way to do it. Any help would be great thank you very much.
 
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  • #2


i apologize i think may be a very stupid question since simple substitution should most likely work but if it doesn't please inform me what i am doing wrong! Thank you again.
 
  • #3


marquitos said:
i apologize i think may be a very stupid question since simple substitution should most likely work but if it doesn't please inform me what i am doing wrong! Thank you again.

The denominator approaches 1, doesn't it? I'm pretty sure the limit does exist.
 
  • #4


Its a theorem that if f, g are continuous and g(x) != 0 then f/g is continuous at x. (1 + y^2) and (x^2 + y^2) are both continuous and (1+y^2) is never zero. Hence (x^2 + y^2)/(1+y^2) is continuous everywhere. So the limit is the value of the function at all points including zero.
 

FAQ: Evaluating Multivariable Limit: (x^2+y^2)/(1+y^2)

What is a multivariable limit?

A multivariable limit is a mathematical concept that describes the behavior of a function as it approaches a certain point in a multi-dimensional space. It involves evaluating the function along different paths or curves approaching the point in question.

How is a multivariable limit calculated?

To calculate a multivariable limit, you need to plug in the values of the variables into the function and simplify the expression as much as possible. Then, you can evaluate the limit by plugging in the values of the variables as they approach the desired point.

Why is it important to evaluate multivariable limits?

Evaluating multivariable limits is important in many areas of mathematics and science, such as in optimization problems, finding critical points, and understanding the behavior of functions in higher dimensions. It also helps to understand the behavior of functions in real-world applications.

What are some common techniques for evaluating multivariable limits?

Some common techniques for evaluating multivariable limits include direct substitution, using algebraic manipulation to simplify the expression, using trigonometric identities, and using the Squeeze Theorem.

What are some common challenges in evaluating multivariable limits?

Some common challenges in evaluating multivariable limits include dealing with indeterminate forms, such as 0/0 or ∞/∞, and having to evaluate limits along multiple paths to determine if they approach the same value. In some cases, it may also be difficult to find a closed-form expression for the limit, requiring the use of numerical methods.

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