Is the function $f(x,y)=xy^{\frac{1}{3}}$ differentiable at $(0,0)$?
31051
Is $f(x,y)=(xy)^{2/3}$ differentiable at $(0,0)$?
19828
Show that $\frac{x^3}{x^2+y^2}$ is not differentiable at $(0,0)$, even though all directional derivatives exist
144773
function $f(x)=x^{-(1/3)}$ , please check whether my solution is correct?
59956
Show that the function $g(x) = x^2 \sin(\frac{1}{x}) ,(g(0) = 0)$ is everywhere differentiable and that $g′(0) = 0$
124346
Where is $f(z)=\Re (z)$ differentiable?
46398
Is $(x^2+y^2+z^2) \ \sin \frac{1}{\sqrt{x^2+y^2+z^2}}$ Differentiable in $(0,0,0)$?
84436
third derivative of inverse function
121455
$f(x)$ if $f(xy)=f(x) +f(y) +\frac{x+y-1}{xy}$
57407
Show that $(x^2 + y^2) \sin\left(\frac{1}{x^2 + y^2}\right)$ is differentiable.
134122
When is differentiating an equation valid?
34136
$f$ is differentiable in $[0,1]$ ,$\sup_{x\in[0,1]}|f'(x)| \le M\lt+\infty $
8659
How do you show that $e^{-1/x^2}$ is differentiable at $0$?
143874
Limit of derivative is zero. Does it imply a limit for f(x)?
66560
Is a differentiable function always continuous?
49705
Is $f(x,y)=(x+2y+y^2+|xy|, 2x+y+x^2+|xy|)$ differentiable?
9211
$\int\frac{dx}{x-3y}$ when $y(x-y)^2=x$?
31685
Differentiability of $f(x) = x^2 \sin{\frac{1}{x}}$ and $f'$