Let f: be given by
f(x,y) :=
if (x,y) (0,0)
0 otherwise
(a) Show that exists for all the vectors and that = if u = (a,b) with a 0.
(b) Show that f is not differentiable at (0,0)
We just started this topic and I am completely lost... please help
Let f: be given by
f(x,y) :=
if (x,y) (0,0)
0 otherwise
(a) Show that exists for all the vectors and that = if u = (a,b) with a 0.
(b) Show that f is not differentiable at (0,0)
We just started this topic and I am completely lost... please help
(1)what is the diefinition of directional derivative? make sure you understand the definition !
If u=(a,b), then (x,y)=(at,bt) tend to (0,0) as t tend to 0, then what is the limit ?
(2) if (x,y) tend to 0 with the path x=ky^2, then what can you say about the limit?