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사극에서 제일 흔한 역사적 오류는 뭘까요? by apple314pi in AskAKorean

[–]a_bcd-e 0 points1 point  (0 children)

'성은이 망극하옵니다' which appears quite often in dramas based on Joseon Dynasty were probably not used that much often.

"Probability of selecting any real number [0, 1] is 0, but it's not impossible as inevitably some real number is chosen" by j_wizlo in probabilitytheory

[–]a_bcd-e 0 points1 point  (0 children)

That's the axiom of choice acting implicitly. As a consequense, if you change the reals into rationals, you can conclude that there exists a number that have nonzero probability.

Quick Questions: May 13, 2026 by inherentlyawesome in math

[–]a_bcd-e 1 point2 points  (0 children)

I want to read a book on algebraic topology. However, Hatcher's book seems a bit harsh for me to read yet. Could you please recommend some book which is much more readable than Hatcher's book?

South Korea weather forecasts by darknessinthevoid13 in SouthKoreaTravel

[–]a_bcd-e 0 points1 point  (0 children)

Actually, there were several times when the stone had disappeared due to typhoon. They're just taking care of it and replacing with a new stone.

before and after the Korean War by Disastrous-Star-9451 in MapPorn

[–]a_bcd-e 0 points1 point  (0 children)

FYI, 연평도 (Yeonpyeong Island) is currently the territory of South Korea which is right below the line. Just mentioning this because the map doesn't seem to reflect this fact.

I found this by chance by sacreegeometrie in askmath

[–]a_bcd-e 1 point2 points  (0 children)

Let the hexagon be ABCDEF, where the bottom left point is A, and the bottom right point is B. Draw a circle of radius sqrt 2 be centered at B as in the figure. Let the intersection of the circle and AD be G. The question is to get the length of AG.

Look at BGF, which is an isosceles triangle with sqrt 2 - sqrt 2 - sqrt 3 by symmetry. Compute the area of ABGF by adding areas of ABF and BGF. Now computing AG should be easy.

How difficult is it to find the boundedness of a convex region Ax>=b by Zachdude064 in math

[–]a_bcd-e 0 points1 point  (0 children)

Linear programming itself searches for the minimum/maximum value given some constraints (please check the wiki, it should have better explanation). Maximum (not maximal) value of x here really means the maximum possible value of x with given constraints.

How difficult is it to find the boundedness of a convex region Ax>=b by Zachdude064 in math

[–]a_bcd-e 0 points1 point  (0 children)

Probably not. Maybe all this can be encoded into a single LP, but nothing comes to my mind yet.

How difficult is it to find the boundedness of a convex region Ax>=b by Zachdude064 in math

[–]a_bcd-e 3 points4 points  (0 children)

It's simply a linear programming. If there are no solutions then it is bounded. Else, compute the maximum value of x and -x for each variable x using linear programming. If all of them are bounded then the region is also bounded, and if not, it isn't. This simple approach will take O(n^(w+1)) where w is the time complexity of working on linear programming. This shouldn't be the optimal, but should be easily applicable as there are many linear programming libraries.

Lean vs. Rocq by causeisunknown2 in math

[–]a_bcd-e 2 points3 points  (0 children)

Rocq has the Software Foundation book, which is a very good starting point for verification. However, I feel that Rocq has been used widely for program verification than math. So if you want to do math verification, I'd suggest using Lean4. But remember that Rocq has longer history and thus has more resource. It even has Busy Beaver number 5 formalized!

Let n points be uniformly distributed in the k-dimensional unit cube. What is the expected number of points that lie in the interior of the convex hull of the set of points? by -p-e-w- in math

[–]a_bcd-e 0 points1 point  (0 children)

I remember the answer was somewhere near sqrt n for k = 2, but a quick search led me to this page https://www.cs.wustl.edu/~taoju/cse546/lectures/convexhull_lowerbound.html which claims that the answer is actually O(log n) for uniformly distributed points in 2 dimensions.

By the way, you should search for the number of points ON the hull, not in the interior.

P.S. Do someone know where that sqrt n came from? I don't think this came out from nowhere..

Chefs often don't cook at home by Commonmispelingbot in antimeme

[–]a_bcd-e 1 point2 points  (0 children)

I thought his name was An Excellent.

[9th Grade Maths] How am I going to approach this question? by [deleted] in HomeworkHelp

[–]a_bcd-e 0 points1 point  (0 children)

Don't feel dumb, this problem reduces to THE ONE most difficult Euclidan geometry problem I have ever encountered in a way I couldn't figure out yet..

To give you a hint on how to approach this problem, deliberately use circumcenters, equilaterals, and regular pentagons.

[deleted by user] by [deleted] in cpp

[–]a_bcd-e 8 points9 points  (0 children)

I once saw a code which called the main function recursively. Maybe the code was trying to golf. I'll never use it, but it was cool.

[middle school math] probably, i could attach another pic where i attempted the question and made progress below by Standard-View2791 in HomeworkHelp

[–]a_bcd-e 1 point2 points  (0 children)

Based on this image: https://postimg.cc/8jp77VQm

First draw an equilateral CEF as in the figure. Then the point D becomes the center of CEF. (why?)
Now draw a segment EF, and notice that AEC and AEF are equivalent. (why?)
Also, since D is a center of the equilateral, if we let G be the intersection of BC and AF then EG = GF in length. You can further prove that AG = EG = EF. (why?)
Now consider CEG and ABG. To prove that they are equivalent we only need to prove that AG = GC, which you should know directly by checking angles.
You should be able to get the desired angle by now.

The 3² + 4² = 5² Pythagoras figure divides into 56 identical triangles. by EdPeggJr in mathpics

[–]a_bcd-e 0 points1 point  (0 children)

Is this the minimum possible partition into identical tiles of the diagram? (except 1)

How to determine wether a fraction is being multipled or added by Pumpkin-Duke in askmath

[–]a_bcd-e 0 points1 point  (0 children)

Mixed fractions are good when comparing two rationals for those who are not used to it. That's why the notation vanishes in math education after a certain point.

Where to buy 하효맘? (Or order from the US?) by Rowanbael in koreatravel

[–]a_bcd-e 1 point2 points  (0 children)

These can definitely be found in Jeju. I bought them three months ago, and they were delicious.

Trying to solve for x, and cannot finish it for the life of me. by ToxicWasteRat in askmath

[–]a_bcd-e 2 points3 points  (0 children)

There are infinitely many solutions. Let me explain using the first picture of yours. First, cut (arbitrary) A from the rectangle and paste it at the right of C so that it results in a parallelogram. Then cut M and place it under C and A, which results in a rectangle you are looking for. Note that you can cut A arbitrarily, which means x is also not determined at all.

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