Can a real function $f$ on $[0,1]\cap\mathbb{Q}$ be differentiable?
100765
If $f'(x) = 0$ for all $x \in \mathbb{Q}$, is $f$ constant?
96547
Is $|z|^2$ complex differentiable?
13150
If the derivative of $f$ is never zero, then $f$ is one-to-one
111470
Proof of differentiability of $f(x)$
40070
Is there a real-valued function $f$ such that $f(f(x)) = -x$?
151575
Differentiable bijection $f:\mathbb{R} \to \mathbb{R}$ with nonzero derivative whose inverse is not differentiable
120118
The distinction between infinitely differentiable function and real analytic function
99984
Are polynomials infinitely many times differentiable?
65953
Cardinality of the set of differentiable functions
135610
How to give an example of a $f$ differentiable in a deleted neighborhood of $x_0$ such that $\lim_{x\to x_0}f^\prime(x)$ doesn't exist?
34136
$f$ is differentiable in $[0,1]$ ,$\sup_{x\in[0,1]}|f'(x)| \le M\lt+\infty $
18734
Showing that a function is differentiable
9270
Differentiable function, with $f'(x)=[f(x)]^2$
40429
Differentiability of this picewise function
69876
For every $n \in \mathbb{N}$, find a function $f$ which is differentiable $n$ times at $0$, but not $n+1$ times.
119602
$f:\mathbb{R} \to \mathbb{R}$ be differentiable and $\lim\limits_{x\to\infty}f'(x)=1$, is $f(x)$ unbounded?
122003
From the limit definition of differentiability, determine where the function $f(x) = \sqrt{x}$ is differentiable?