Define when a function $$f:D\rightarrow \mathbb{R}, D\subset \mathbb{R}$$ differentiable in one point $$x \in D$$ is

Question

Define when a function $$f:D\rightarrow \mathbb{R}, D\subset \mathbb{R}$$ differentiable in one point  $$x \in D$$ is

mathmath333 · Answer

i m not expert in group theory 
but this people can help

mathmath333 · Answer

@Loser66 
@ikram002p

ikram002p · Answer

whats the question ?
do u have specific function or in general ?

anonymous · Answer

@ikram i am not sure, i think its general, cause all i have is that question, unfortunately not any more information

ikram002p · Answer

oh i see , i just need u to define what is D in ur txt book , could u post that ?

anonymous · Answer

that was in my exam, but really it s all what i have as information, but i think its a general function

ikram002p · Answer

is it  only subset from R , or a  special group ?

anonymous · Answer

i think its only subset from  R

ikram002p · Answer

oh i see , i asked since sometimes they give such special groups in txt book , then ask u as if u already know it .

anonymous · Answer

yeah i understand what u mean no problem

ikram002p · Answer

Define when a function 
f:D→R,D⊂R
 differentiable in one point  

assume this function on D (x0,x1)
u could see that range is all R , right ?
x∈D|dw:1413748257013:dw|

anonymous · Answer

ok..

ikram002p · Answer

now we easily say , its smooth function 
also  differentiable for all x in Domain , right ? |dw:1413748454533:dw|