Infinite differentiablility at $0$ of a piecewise function
116520
formula for the $n$th derivative of $e^{-1/x^2}$
83915
Showing that a function is not differentiable
31051
Is $f(x,y)=(xy)^{2/3}$ differentiable at $(0,0)$?
91123
A convex function is differentiable at all but countably many points
97382
Continuous differentiability implies Lipschitz continuity
5625
Entire function with vanishing derivatives?
48464
If the derivative approaches zero then the limit exists
140445
Sequence of continuous functions whose pointwise limit is discontinuous
18825
Integrable but not differentiable function
83517
Taylor series of Infinitely differentiable function with nonnegative derivatives
34187
The limit of the derivative of an increasing and bounded function is always $0$?
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 $x_{0} = 0$ `
135199
Looking for a function $f$ that is $n$-differentiable, but $f^{(n)}$ is not continuous
40429
Differentiability of this picewise function
99795
Derivative of piece-wise function given by $x\sin\frac1x$ at $x=0$
1014
Pointwise limit of continuous functions not Riemann integrable
152328
A continuously differentiable map is locally Lipschitz