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/sci/ - Science & Math

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11250640 No.11250640 [Reply] [Original]

In the 1970's and 1980's there was discrimination against Jews in Soviet universities. The mathematics entry exam for admission to Moscow State University included a number of contrived problems given to Jewish candidates. Here I present one selected anti-semitic geometry problem.

K is the midpoint of a chord AB. MN and ST are chords that pass through K. MT intersects AK at point P and NS intersects KB at point Q. Show that KP = KQ.

>> No.11250692 [DELETED] 

>>11250640
I'm not going to do your homework problem but someone applying to a Soviet University for math should be able to do this by the age of 16.

>> No.11250698 [DELETED] 

>>11250640
You can find me on Chegg @ John C. Search this question on high school geometry and I'll help you out with a 15 minute written lesson.

>> No.11250715
File: 94 KB, 836x780, 2019-12-24_23.06.42.jpg [View same] [iqdb] [saucenao] [google]
11250715

>>11250640
> MT intersects AK at point P
Explain.

>> No.11250726

>>11250715
Its a mistake in the statement. It should instead state MT intersects KB at point P and NS intersects AK at Q.

I am mainly interested if this problem is as hard as the book on Soviet mathematics I'm reading now claims. So far no one has provided a solution.

>> No.11250727
File: 152 KB, 960x720, 1577065102101.jpg [View same] [iqdb] [saucenao] [google]
11250727

>>11250640
KP = 1.2cm
KQ = 1.2cm
KP=KQ

>> No.11250729
File: 69 KB, 340x372, 1557607476346.jpg [View same] [iqdb] [saucenao] [google]
11250729

>>11250726

It seriously confused me.

>> No.11250779

OK so nobody can solve a seemingly simple highschool geometry problem?

>> No.11250788

>>11250779
seems so

>> No.11250797

>>11250640
>Show that KP = KQ.
But that isn't true?

>> No.11250804

>>11250640
The first step I would do is turning the problem upside down, on its head.

You have a triangle, that triangle defines a circle. You can choose any not yet designated point of the square as the fourth vertex of your now quadrilateral.

The point of intersection of quadrilateral's diagonals, if not coinciding with the circle's center, uniquely defines the horde the initial formulation of the problem starts with.

In other words, you get to the picture, that happens to look the same by means of entirely different constructing algorithm. This is, I believe, commonly called "out of the box" thinking. Maybe this time around it will become more solvable. Then again, maybe not. Can't ass to actually verify it.

>> No.11250809

>>11250804
>any not yet designated point of the circle as the fourth vertex of your now quadrilateral
Fix.

In other words, this kind of construction reversal is how I think that problem became a thing to begin with, I am reversing this assumed reversal back to its assumed initial state.

In other words, I suspect this is a bullshit problem which rests entirely on obfuscation.

>> No.11250811

>>11250727
>1.2cm
with ruler on the screen?

>> No.11250858

>>11250640
>discrimination against Jews
I call it affirmative action for goyim.

>> No.11250859

>>11250640
https://www.ams.org/notices/201311/rnoti-p1448.pdf

>> No.11250861

>>11250779
The whole point of these problems is that they're "seemingly simple" but secretly bullshit

>> No.11250878
File: 742 KB, 1785x1447, __flandre_scarlet_and_remilia_scarlet_touhou_drawn_by_toutenkou__2bbbc982b352fe8d084faf7425e598e5.jpg [View same] [iqdb] [saucenao] [google]
11250878

Ahem, excuse me, I happen to be an expert on the subject.
That's the butterfly theorem.

>> No.11250880

>>11250640
>Semitic
Just call them gypsies. Nobody gives a fuck about middle easterns calling themselves 3000 different names and "that's fursection" like the bronies and furries do "i'm a different kind of diarrhea please respect my special snowflake-ness". Fuck them.

>> No.11250887

>>11250878
Care to explain the proper approach or solution?

>> No.11250895
File: 258 KB, 800x776, __flandre_scarlet_and_remilia_scarlet_touhou_drawn_by_noai_nioshi__cbe1bf789704d4ac0a7e8db446c74437.jpg [View same] [iqdb] [saucenao] [google]
11250895

>>11250887
The wikipedia page has a proof.

>> No.11250897

>>11250895
Yes, I just saw. Very cool!

>> No.11250914

>>11250878
>That's the butterfly theorem.
Cool, I didn't know it had a wikipedia page. Below you can find the source of the problem and a few different solutions.

https://books.google.at/books/about/You_Failed_Your_Math_Test_Comrade_Einste.html?id=-aHICgAAQBAJ&printsec=frontcover&source=kp_read_button&redir_esc=y#v=onepage&q&f=false

>> No.11250939

>>11250880
Semite is the actual not only ethnic name, but also linguistic. Cope, whatever Gypsy mean

>> No.11251915

>>11250640
since cross ratios are preserved under homographies, project from S the pencil (A,K;Q,B) to (A,T;N,B), then project this one from M to (A,P;K,B). calculating that KQ=KP from here is obvious.

>> No.11252068

>>11250640
If you find the similar angles and lengths the answer is obvious.

>> No.11252072

>>11250640
everyone saw that book, its pretty gay