3,347 reputation
21034
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location Buenos Aires, Argentina
age 21
visits member for 4 years, 2 months
seen 37 mins ago

(my about me is currently blank)


Aug
10
comment Is my proof correct about limit of $\sin\left(\frac{1}{x}\right)$?
It's not a big deal, but you should mention what happens when $|A| > 1$.
Aug
7
comment Differentiate $\ln(\cos2x)$ With respect to $x$.
@Amzoti: Please, there's no need to be like that. I understand what you wrote, and the asker of the question does too. But if you read my comment, you'll see that not only did I not even begin to imply that something was offensive, but also that I think that writing things like $\ln u =\frac1{u}$ only helps further the confusion of students who write that when asked to differentiate $\ln u$.
Aug
7
comment Differentiate $\ln(\cos2x)$ With respect to $x$.
Yes, please don't write things like $\ln u = \frac1{u}$. Students are confused enough already. Either say $(\ln u)'$, or $\frac{d}{du}\ln u$, or else "the derivative of $\ln u$ is $\frac1{u}$".
Aug
6
comment Are parallel vectors always scalar multiple of each others?
@AmitTomar: So really any lines that don't intersect? Because that's not the definition of parallel.
Aug
6
comment Are parallel vectors always scalar multiple of each others?
Could you clarify what you mean by parallel lines that are not in the same direction? Do you mean parallel lines that don't touch, or do you mean lines that have different direction vectors and don't intersect? The latter are called skew lines.
Aug
6
comment Are parallel vectors always scalar multiple of each others?
@Kaster: I think I may be misunderstanding the OP's question. Let me ask.
Aug
6
comment Are parallel vectors always scalar multiple of each others?
@user142526: I din't word that very well. Let me fix it.
Aug
5
comment Explain this step in logarithms
Your answer seems fine.
Aug
3
comment Trying to reverse an equation and solve for a different variable
Well, technically you can't reverse it, since because of the floor function many different xps will give the same level. But you can find out the minimum xp required to reach each level (I'm assuming this is for a game).
Jul
31
comment Prove: $\int_0^{\infty}\left(\frac{\sin x}{x}\right)^2dx=\pi/2$
Presumably you mean $|x| \le \delta$ instead of $x \le |\delta|$ in the definition of $f$?
Jul
27
comment Dot Product/ Cross Product Proof
You're using the same $\theta$ for everything. That's not correct.
Jul
21
comment How can the graph of a complex function be embedded in three dimensional space?
@JoeHobbit: What do you mean? Could you give an example?
Jul
18
comment is this the right truth table?
Small nitpick: the fifth row is correct too.
Jul
14
comment Unique root to a function
Words?${}{}{}{}{}{}$
Jul
9
comment Evaluate $\int \limits_{0}^{\infty} \frac{x}{1+x^2} dx$
If you could overcome lack of convergence, no one would bother with convergence tests.
Jul
8
comment Incorrect notation in math?
Isn't it $-3/2$ in the exponent?
Jul
8
comment Incorrect notation in math?
All those notation are correct, if a bit confusing. But there exist incorrect notations, of course.
Jul
7
comment Complex integral $\frac {1}{1+z}$
I'm not sure I understand what path you're supposed to integrate on.
Jul
4
comment Proving the Product Rule for exponents with the same base
How do you define this when $b$ and $c$ are not rational?
Jul
3
comment derivative of $f(x)=\frac{x}{x-1}$
Do you know how to use the quotient rule? What are you having trouble with specifically?