Reputation
12,067
Top tag
Next privilege 15,000 Rep.
Protect questions
Badges
4 25 64
Impact
~169k people reached

Jun
30
comment Integral involving a trig. term
Doesn't the fact that you've written the $dx$ to the left of the function you are trying to integrate matter? (I understand what you're saying, and my comment is entirely tangential: I just feel that what you've written doesn't actually makes sense, but would be interested if my intuition was wrong...)
Jun
25
comment How to integrate $\int^{\infty}_{-\infty} e^{-2\pi^2/x^2} dx$?
You need brackets. Do you mean $\displaystyle\frac{e^{-2\pi}}{x^2}$? Or $\displaystyle\frac{e^{-2}\pi}{x^2}$ Or $\displaystyle\left(\frac{e^{-2\pi}}{x}\right)^2$? Or something else?
Jun
25
asked $e^{i\theta}$ versus $\cos\theta+i\sin\theta$
Jun
15
revised Is every normal subgroup of a finitely generated free group a normal closure of a finite set?
added 156 characters in body
Jun
15
revised Is every normal subgroup of a finitely generated free group a normal closure of a finite set?
added 109 characters in body
Jun
15
answered Is every normal subgroup of a finitely generated free group a normal closure of a finite set?
Jun
15
comment How do I simplify the answer?
...assuming $x\neq-1$...
Jun
15
comment How do I simplify the answer?
@ClementC. I agree on all counts.
Jun
15
comment How do I simplify the answer?
I think downvoting this answer is not helpful, because the answer is itself helpful. Clearly the OP is having issues with the step given by the hint - the incorrect derivative is, in a certain sense, circumstantial.
Jun
15
revised How do I simplify the answer?
added 4 characters in body
Jun
1
comment Quotient of the Baumslag-Solitar group $BS(1,m)=\langle a,b| bab^{-1}=a^m\rangle$
@Derek Thanks. Again, I was too hasty!
Jun
1
comment Quotient of the Baumslag-Solitar group $BS(1,m)=\langle a,b| bab^{-1}=a^m\rangle$
@Derek Why is every element of $N$ conjugate to a power of $a$? For example, $b^{-1}aba^m\in N$, and by the conjugacy theorem for HNN-extensions we would need that $a^ib^{-1}aba^j=a^k$, which does not hold. No?
Jun
1
comment Quotient of the Baumslag-Solitar group $BS(1,m)=\langle a,b| bab^{-1}=a^m\rangle$
@Derek Thanks - I was too hasty. I've deleted both my comments.
May
29
revised Groups occuring as derived subgroups.
added 77 characters in body; edited title
May
19
revised Show that $\alpha: G \rightarrow G ,\alpha(g)=g^2$ isomorphism
added 2 characters in body
May
19
comment Show that $\alpha: G \rightarrow G ,\alpha(g)=g^2$ isomorphism
@ASKASK Yeah, probably. But still - at least write out the word fully!
May
19
comment Show that $\alpha: G \rightarrow G ,\alpha(g)=g^2$ isomorphism
I do not understand your attempt. What is "hom", and why is $G$ this?
May
19
revised Why Aren't “Similar” Matrices Actually the Same?
I used to be called Swlabr, a long time ago.
May
15
comment What does this vector notation really mean?
@vadim123 C'mon, this is a valid question. A similar one might be Is “a+0i” in every way equal to just “a”?.
May
13
revised Proof that elements of a free generating set have infinite order.
deleted 3 characters in body