Tab Content
• Today, 18:27
Conceptually an integral corresponds to the area under a graph. If that graph extends to infinity, the height of the graph must approach zero, since...
11 replies | 130 view(s)
• Today, 18:06
Erm... then I'm not quite sure what I can use or not. Can you perhaps use the fact that a series $x_1 + x_2 + ...$ can only converge if $x_n \to 0$?...
11 replies | 130 view(s)
• Today, 17:39
What is the regular/basic definition of limits that you are familiar with? The generic definition is the so-called $\varepsilon$-$\delta$...
11 replies | 130 view(s)
• Today, 16:37
The multiplicative inverse of q with respect to q'. That is, it is such that: $$_{q'}^{-1} \cdot q \equiv 1 \pmod {q'}$$ And since $q$ and $q'$...
4 replies | 58 view(s)
• Today, 16:10
Suppose $\lim\limits_{x\to\infty} f(x)=c > 0$. Then for $\varepsilon = \frac c 2 > 0$ there must be some $a$ such that for every $x>a$ we have that...
11 replies | 130 view(s)
• Today, 15:36
Hey MermaidWonders! Let's start with $\int_0^{\infty} f(x)\,dx$, which must also converge. Then $\lim\limits_{{x}\to{\infty}}f(x) = 0$ isn't it?...
11 replies | 130 view(s)
• Today, 15:23
Hi steenis, Suppose $\gcd(m,m')=d$, then we can write $m=qd$ and $m'=q'd$ with $\gcd(q,q')=1$. And suppose $b\equiv b' \pmod d$, so that...
4 replies | 58 view(s)
• Today, 13:34
$$\int_1^{\infty}\frac1x \, dx$$ does not converge. If you were to try to get an antiderivative, the only candidate is $\ln|x|$, so formally, you'd...
3 replies | 50 view(s)
• Today, 07:38
I am reading "Multidimensional Real Analysis I: Differentiation" by J. J. Duistermaat and J. A. C. Kolk ... I am focused on Chapter 2:...
1 replies | 30 view(s)
• Today, 06:50
I am reading "Multidimensional Real Analysis I: Differentiation" by J. J. Duistermaat and J. A. C. Kolk ... I am focused on Chapter 2:...
0 replies | 20 view(s)
• Today, 00:31
\frac{5}{4}\cdot\frac{4}{3}=\frac{5}{3} :)
14 replies | 212 view(s)
• Yesterday, 23:10
MarkFL posted a visitor message on Peter's profile
Sometimes editing a thread title is an issue, but the issue is with vBulletin. If you ever want to change a thread title, and can't, just let me know...
• Yesterday, 22:24
Thanks again Krylov .... BUT ... just a comment on D&K's proof .... I have to say that D&K's proof of Hadamard's Lemma though valid, is not...
3 replies | 72 view(s)
• Yesterday, 21:57
I am reading "Multidimensional Real Analysis I: Differentiation" by J. J. Duistermaat and J. A. C. Kolk ... I am focused on Chapter 2:...
0 replies | 22 view(s)
• Yesterday, 21:26
I am reading "Multidimensional Real Analysis I: Differentiation" by J. J. Duistermaat and J. A. C. Kolk ... I am focused on Chapter 2:...
1 replies | 44 view(s)
• Yesterday, 20:41
Thanks Krylov, ... followed your advice and obtained the result ... Thanks again ... Peter
3 replies | 72 view(s)
• Yesterday, 17:09
I'm going to walk through this problem, using your substitution...let's begin with: I=\int_{0}^{\Large\frac{3\pi}{4}}\int_{0}^{\pi}\int_{0}^{1}...
14 replies | 212 view(s)
• Yesterday, 16:30
I think we have no concavity if $f''(x)=0$ for all $x$ in the domain. However, if we have $f''(x)=0$ only on part of the domain, the function can...
20 replies | 238 view(s)
• Yesterday, 16:30
Where did the $\cos(\theta)$ come from?
14 replies | 212 view(s)
• Yesterday, 16:28
I was simply taught that a linear function has no concavity...just recalling from memory. :)
20 replies | 238 view(s)
• Yesterday, 16:24
Let's look at an example that more clearly demonstrates the statement regarding concavity isn't always true. Consider: H(x)=\ln(x+1) And so: ...
20 replies | 238 view(s)
• Yesterday, 16:21
I can only refer to the wiki page, which is consistent with what I've learned. And I've never heard or seen that it could be different. Can you...
20 replies | 238 view(s)
• Yesterday, 16:19
With the given information we can conclude that $H'(x)>0$ on the unit interval due to the Fundamental Theorem of Calculus, meaning it's strictly...
20 replies | 238 view(s)
• Yesterday, 16:07
Correct. (Nod)
20 replies | 238 view(s)
• Yesterday, 15:58
Perhaps there are differences in terminology...I was taught that a function is concave up on an interval when its second derivative is positive, and...
20 replies | 238 view(s)
More Activity

### 24 Visitor Messages

1. Thanks Fantini
2. Haha. \widehat's cool. Also check out \widetilde. But these sometimes get ugly.
3. Yep. Corrected now.
4. Thanks for the thanks. For what it's worth, I have already let Jameson know that an option to turn off or disable the social media buttons would be a good idea in my opinion.
5. Hey, good catch...that is in fact what I meant to type, but my darn keyboard seems to have a mind of its own at times. Thanks for letting me know so I could fix it.
6. Yes thanks Fantini, edited
7. Not at all...it's GOOD to think about these things.
8. Fantini, have I seen you on SE before?
9. Fantini - Hey, thanks! Yeah, the colors go well together, I think. Bach was the greatest!
10. Hey Fantini . I reported the thread so the Mods in green can decide where to put it. I don't mess with topics I'm not very familiar with haha.
Showing Visitor Messages 1 to 10 of 24
Page 1 of 3 123 Last
Page 1 of 3 123 Last

#### Basic Information

Age
26
Location:
Brazil
Interests:
Mathematics, Physics, Engineering, Philosophy, Sociology, Neuroscience
Occupation:
Country Flag:
Brazil

#### Statistics

Total Posts
334
Posts Per Day
0.15
Thanks Given
1,345
778
2.329
##### Visitor Messages
Total Messages
24
Most Recent Message
December 21st, 2014 09:30
##### General Information
Last Activity
December 15th, 2017 09:17
Last Visit
December 11th, 2017 at 02:13
Last Post
September 25th, 2017 at 16:16
Join Date
February 29th, 2012

### 25 Friends

1. #### AckbachOffline

Indicium Physicus

2. #### alane1994Offline

MHB Craftsman

3. #### BacteriusOffline

MHB Journeyman

4. #### caffeinemachineOffline

MHB Journeyman

MHB Master

6. #### Chris L T521Offline

MHB Journeyman

MHB Master

MHB Master

MHB Master

10. #### Fernando RevillaOffline

MHB Journeyman

Showing Friends 1 to 10 of 25
Page 1 of 3 123 Last