I recently entered this post about self-sliding surfaces. They are surfaces that remain invariant under a constant "screw-motion", i.e. the combination of a rotation around an axis and a translation in the same direction (with special cases of no rotation or no translation). Concretely, they are ...
I've found the following theorem for single variable real valued functions:
The converse of the chain rule: Suppose that $f,g$ and $u$ are related so that $f(x)=g(u(x))$. If $u$ is continuous at $x_0$, $f'(x_0)$ exists and $g'(u(x_0))$ exists and is non-zero; then $u'(x_0)$ is defined and we ...
I have the following theorem:
If $F$ is a vector field defined in a simply-connected open set, whose coordinate functions have continuous partial derivatives and $curl(F)=0$, then $F$ is conservative.
I'm asking if the converse also holds or which additional hipotesis would make it hold.
Thanks
Can you change the name of a tag? I recently came across the tag sage, which I think should be renamed to sagemath to be more clear.
Is it possible to change the name of a tag? If so, how?
If this is not possible and people support this renaming, I can create a new tag called sagemath and h...
@wythagoras What exactly does that column merge in the list of tag synonyms mean. The tooltip says "active synonyms requiring a merge". Is that simply the list of synonyms where at least one question is tagged by a slave tags.
Personally, I am not that keen on merging tags (in addition to synonymizing them). I do not see any great advantage. If the tags are not merged, it makes things a bit easier in the cases when synonym is cancelled. See: What happens with the tagged questions when a tag-synonym is cancelled?
And also one of these three questions - Calculating the modulus - has nothing to do with modulus theorem. Which might leave us with two questions in that tag.