Differentiability at a point x=0
6417
Can a function be differentiable at the end points of its (closed interval) domain?
30533
Showing that this function is infinitely differentiable
147758
Differentiable but not continuously differentiable.
130322
Show that $f(x) = 0$ if $x = 0$ $f(x) = \text{exp}(-1/x^{2})$ if $x \neq 0$ is infinitely differentiable but not analytic at $x_{0} = 0$ `
33130
$f$ differentiable except in $1$ point
19828
Show that $\frac{x^3}{x^2+y^2}$ is not differentiable at $(0,0)$, even though all directional derivatives exist
38923
What can we say about differentiability of $f$ at $c$?
91123
A convex function is differentiable at all but countably many points
143491
Show that $f$ is differentiable on $(−1, 1)$.
39057
Check the differentiablity of $\theta :\mathbb R^2 \setminus\{(0,0)\}\to \mathbb R$
75932
Differentiability of $g:=f(\sqrt{x^2+y^2})$ for a $C^1$ function with $f'(0)=0$ NBHM $2008$
18734
Showing that a function is differentiable
16291
Discontinuous derivative.
37850
Does the everywhere differentiability of $f$ imply it is absolutely continuous on a compact interval?
158681
How to show that $e^x$ is differentiable?
142870
Prove the function is not differentiable at (0,0)
119907
Finding the Derivative of |x| using the Limit Definition