When is a function differentiable? ...
I need to prove from the definition of defferntiability that the function
f(x)= 2x-1/x-2
is differentiable at the point 1 and find f'(1)
So far I have
The difference quotient for f at 1 is
Q(h) = f(h)-f(1)/h
= 2h-1/h-2 + 1 / h
= ?
can anyone help?
find a common denominator, cancel any like terms and then find the limit of h->0, if you get (some number)/0 then the function is not differentiable, however if you get 0/0 you get an indeterminate so then you must try another technique (the second derivative).
Sorry I should have said this before: a function is differentiable if
A) f(a) exist
B) limit as x approaches a exist
C) f'(a) exist
D) and f(a) equals the limit as x approaches a
I think that ur function does all of the above...hope this Helps!