- #1
demonelite123
- 219
- 0
lim (sqrt(|x|)y) / (x^2+y^2)
(x,y) -> (0,0)
so I've substituted y = x, y = sqrt(|x|) as well as the substitutions for polar coordinates. the function seems to approach infinite which means that the limit does not exist. the problem asks to show whether the limit exists or not and then to prove it.
i am a little unsure how to prove that it doesn't exist. in the case where i substitute y = x i get lim as (x,y)->(0,0) of sqrt(x) / 2x which simplifies to 1 / 2sqrt(x). i then say that as x approaches 0 then the quantity approaches infinite so the limit does not exist.
does that constitute an actual "proof" or is it too "hand-wavy". if so how would i truly prove this statement? thanks
(x,y) -> (0,0)
so I've substituted y = x, y = sqrt(|x|) as well as the substitutions for polar coordinates. the function seems to approach infinite which means that the limit does not exist. the problem asks to show whether the limit exists or not and then to prove it.
i am a little unsure how to prove that it doesn't exist. in the case where i substitute y = x i get lim as (x,y)->(0,0) of sqrt(x) / 2x which simplifies to 1 / 2sqrt(x). i then say that as x approaches 0 then the quantity approaches infinite so the limit does not exist.
does that constitute an actual "proof" or is it too "hand-wavy". if so how would i truly prove this statement? thanks