Evaluate the limit, if it exists, or show that the limit does not exist. (a) lim (x,y)→(0,0) 5x + y √ 5x + y + 9 − 3 (b) lim (x,y)→(0,0) 2xy x 2 + y 2

Respuesta :

Answer:

Step-by-step explanation:

GIven that :

(a) lim (x,y)→(0,0) 5x + y √ 5x + y + 9 − 3

(b) lim (x,y)→(0,0) 2xy x 2 + y 2

We are to evaluate and determine if the limit exist or not.

From (a);

[tex]\lim \limits _{x \to y (0,0) } 5x + y \sqrt{5x} + y + 9 - 3[/tex]

x = 0

y = 0    (Since no presence of indeterminate)

= [tex]} 5(0 )+ y \sqrt{5(0)} + (0) + 9 - 3[/tex]

= 0+0+0 +9 - 3

= 6

Therefore; the limit exist

(b)

[tex]\lim \limits _{x \to y (0,0) } \dfrac{2xy}{x^2+y^2}[/tex]

If  y = mx

[tex]\lim \limits _{x \to y (0,0) } \dfrac{2(mx^2)}{x^2+(mx)^2}[/tex]

[tex]\lim \limits _{x \to y (0,0) } \dfrac{2(mx^2)}{x^2+(m^2x^2)}[/tex]

[tex]= \dfrac{2m }{1+m^2}[/tex]

So;  the limit depends  on the value of m; then the limit does not exist