The tag algebraic-numbers is created recently. Do we need such a tag? I suggest to make it a synonym of abstract-algebra (or transcendental-numbers) or just remove it.
I have $\vec{a}\times(\vec{a}\times\vec{R})-\vec{b}\times(\vec{b}\times\vec{R})$, my textbook says that this equals $((\vec{a}\times\vec{a})-(\vec{b}\times\vec{b}))\times\vec{R}=-(a^2-b^2)\vec{R}$. I know that the final answer is correct, but is the first step correct as well? (I don't think so, ...
Is vector-analysis correct tag for that question? According to the description this tag is for: Questions related to understanding line integrals, vector fields, surface integrals, the theorems of Gauss, Green and Stokes. Some related tags are (multivariable-calculus) and (differential-geometry).
What tag should i use for "algebra with vectors" - various manipulations with cross product, triple product etc.
The contradiction tag has been discussed previously, here. It was also mentioned in the tag management thread.
On both accounts, it was reasonably favoured that something ought to be done about it. Looking at the questions, the only constant among them is the occurrence of the word "contradictio...