- #1
Kenneth1997
- 21
- 2
x*abs(y)*(y+x^2+x)=f(x,y)
so, on normal points they are tangent vectors on some point in the chosen direction. how about in critical points, where there shouldn't be any on a geometrical standpoint? can i say they exist if i get them with the definition? or the result i get has no value?
like for example on f(0,0), i get 0 for any derivative. do i say they exist and their value is 0 or what?
when a directional derivative don't exist?
so, on normal points they are tangent vectors on some point in the chosen direction. how about in critical points, where there shouldn't be any on a geometrical standpoint? can i say they exist if i get them with the definition? or the result i get has no value?
like for example on f(0,0), i get 0 for any derivative. do i say they exist and their value is 0 or what?
when a directional derivative don't exist?