192 reputation
6
bio website
location
age
visits member for 2 years, 4 months
seen Jan 16 at 1:02

Jul
9
comment Can a transformation of the linear equation system of a LOP change its solution?
Linear optimization problem - sorry I assumed that was a common abbreviation. $\mathfrak{x}$ is just a fancy way of writing $x$, we use this to make it easier to differentiate scalar values from vectors in equations. I just solved the problem normally - I triple checked it, and I even used an online solver, and we'd all get the same answer here.
Jun
24
comment What is the maximum of a set of random variables?
@Dominik Just to make sure - a random variable is uniformly distributed in $[a,b]$ if it is linear in $[a,b]$ and constant $0$ otherwise, and $Y_i$ is still uniformly distributed in $[0,2\vartheta]$ because you just changed the slope, not the fact that it's linear in $[0,2\vartheta]$?
Jun
23
comment What is the maximum of a set of random variables?
I thought I had gotten it for a sec, but... why is the EV the same for $\max X_i$ and $\max Y_i$ again?
Jun
23
comment What is the maximum of a set of random variables?
I get it, but I can't quite imagine how you'd get the idea for this - did you start form the assumption that it's $2\theta$ and worked backwards from there?
Jun
23
comment What is the maximum of a set of random variables?
wikipedia said expected value and mean mean the same thing, changed it though.
Jun
23
comment What is the maximum of a set of random variables?
Oh. That makes sense. Not sure how to work with that, but at least I know where to start now.
Nov
29
comment Proving that idempotence follows from other lattice axioms
You gotta love how these things always seem so stupidly obvious once someone tells you.
Jul
1
comment Solving $y'' - \frac{1}{x} y' + (1+\frac{\cot x}{x}) y = 0$ by rank reduction
Thanks. As it turns out, that was my solution, I just made an error copying it over.
Jul
1
comment Solving $y'' - \frac{1}{x} y' + (1+\frac{\cot x}{x}) y = 0$ by rank reduction
I get $y''(x) = -\sin(x) \int_0^x u(t) dt + \cos(x) u(x) + \cos(x) u(x) + \sin(x) u'(x)$ - I have no idea where you got the '-' in front of the second cos from. $cx^2\sin x$ can't be the solution because $\sin x$ is a solution.
Jun
19
comment Does a closed form sum for this fourier series exist?
Yep, as it turns out my fourier series was wrong (again). It should have been $\frac{(a+b)(-1)^{n+1}}{n}$ where it says b-a in the series (I missed a '-' in the scalar product). Yeah, but I don't think I'm gonna include a closed form for the sum in my homework after all - what you just said is a little over my head, we just briefly touched fourier series in 2 or 3 classes and then went on to the next topic.
Jun
19
comment Does a closed form sum for this fourier series exist?
I guess that makes sense, except I have no idea how to prove these sums either. Do you happen to know what causes my problem with (a=b)?
Jun
18
comment Does a closed form sum for this fourier series exist?
This isn't part of the question title - but I now noticed that this doesn't work with a=b - the sum of the series would become 0. But f(x) is not constant 0 for a=b... But I don't recall having made assumptions about a and b not being equal in my calculations...
Jun
18
comment Fourier-Series of a part-wise defined function?
I see. Unfortunately I don't have the time to fix this before I hand it in, but it will certainly be useful in the future. Thanks.
Jun
17
comment Partial Integration - Where did I go wrong?
Thanks. I "fixed" the sign when I wrote this by accident (I had it right in my notes, then for some reason when I wrote it here I thought it was wrong).
May
30
comment Lagrange multiplier - find minima of a function satisfying a condition
Thanks. Will do.
May
30
comment Lagrange multiplier - find minima of a function satisfying a condition
I don't know, I am using the notation I am used to. But unless the distance happens to be 1, why would I be able to use the square of the distance rather than the distance? EDIT: Actually, that makes sense because I can just take the square root when I have the result... EDIT2: Your signs seem off though.
May
6
comment WolframAlpha blows simple substitution?
My derivative may be wrong - I will check that right away - but I didn't ask WolframAlpha to calculate the derivative, I asked it to calculate my formula for the derivative for a given n.
May
5
comment Doubt about function value (expected undefined, but Wolframalpha says otherwise)
Actually, our Prof is very thorough when it comes to those kind of things, I just wasn't sure if it was actually ok to fix the singularity in this case...
May
5
comment Doubt about function value (expected undefined, but Wolframalpha says otherwise)
Can I just do it like that? Granted, the original function is continuous at $-1/3$ so I can probably do that in this case, but are such things ok in general?
May
5
comment Doubt about function value (expected undefined, but Wolframalpha says otherwise)
1 + (12x+4)/((x+1)^2) * (12/(12x+4) - 2/(x+1)), x=-1/3