(1 point) Show that the function f(x,y)=x2yx4+y2. f(x,y)=x2yx4+y2. does not have a limit at (0,0)(0,0) by examining the following limits. (a) Find the limit of ff as (x,y)→(0,0)(x,y)→(0,0) along the line y=xy=x. lim(x,y)→(0,0)y=xf(x,y)=limy=x(x,y)→(0,0)f(x,y)= (b) Find the limit of ff as (x,y)→(0,0)(x,y)→(0,0) along the curve y=x2y=x2. lim(x,y)→(0,0)y=x2f(x,y)=limy=x2(x,y)→(0,0)f(x,y)= (Be sure that you are able to explain why the results in (a) and (b) indicate that ff does not have a limit at (0,0)!

Respuesta :

Note: The function is poorly written, so we'll assume a better expression. You can use this answer as a guide for the real question

Answer:

Explanation below

Step-by-step explanation:

Two-Variable Limits

Given a two-variable function f(x,y), we need to compute if

[tex]\lim\limits_{(x,y) \rightarrow (0,0)}f(x,y)[/tex]

exists, being

[tex]\displaystyle f(x,y)=\frac{x^2y}{x^4+y^2}[/tex]

a) We'll use the function y=x to approach the point (0,0):

[tex]\displaystyle \lim\limits_{(x,y) \rightarrow (0,0)}\frac{x^2y}{x^4+y^2}[/tex]

Since y=x

[tex]=\displaystyle \lim\limits_{(x,y) \rightarrow (0,0)}\frac{x^3}{x^4+x^2}[/tex]

Factoring

[tex]=\displaystyle \lim\limits_{(x,y) \rightarrow (0,0)}\frac{x^3}{x^2(x^2+1)}[/tex]

Simplifying

[tex]=\displaystyle \lim\limits_{(x,y) \rightarrow (0,0)}\frac{x}{x^2+1}=0[/tex]

The limit gives 0

(b) Now we'll use [tex]y=x^2[/tex] to approach the point (0,0). We compute the limit again

[tex]\displaystyle \lim\limits_{(x,y) \rightarrow (0,0)}\frac{x^2y}{x^4+y^2}[/tex]

Plugging in [tex]y=x^2[/tex]

[tex]\displaystyle =\lim\limits_{(x,y) \rightarrow (0,0)}\frac{x^4}{x^4+x^4}[/tex]

Simplifying

[tex]\displaystyle =\lim\limits_{(x,y) \rightarrow (0,0)}\frac{1}{2}[/tex]

The limit gives 1/2

Since both limits are different, the limit does not exist