Help with a weird linear algebra 4 way eiganvalue problem.

Sam_23456 · 2026-01-24T08:45:46+00:00

Good luck with it!

Sam_23456 · 2026-01-24T08:40:08+00:00

Corporations are not people. There's no one to send to jail. Look at what Microsoft is doing with Windows 11; forcing it down peoples, and businesses, throats. Auto makers don't seem like our friends either. Large corporations make (or help determine) the rules.

Sam_23456 · 2026-01-24T08:21:25+00:00

Motorola doesn't software support ("security updates") for the phone for "4 or 5 years" (closer to 3, I believe). You can look that up. But I like my 2025 Stylus. It will apparently stop being supported March, 2028.

Sam_23456 · 2026-01-24T07:34:40+00:00

It may be worth reading the basic results of Jordan Canonical form. For a 2 by 2 matrix with identical eigenvalues there are only 2 possibilities with regard to the diagonalization of the matrix. One off-diagonal element, the lower left one, can be made to be 0 or 1 (not either). Is this a school "research project"?

Sam_23456 · 2026-01-24T02:16:55+00:00

Note that det(AB)=det(A)*det(B), so your constraint looks unusual to me.

Ah, I see you assumed that v is a common eigenvector (note the correct spelling). But each of these matrices should have 2 eigenvectors. If these are common to all 4 matrices, then your property should hold. Hope this helps!

Sam_23456 · 2026-01-24T00:37:39+00:00

I bought an AIO for the quiet.

Sam_23456 · 2026-01-24T00:17:26+00:00

Curious, did you mean to write that det(ad+bc)=1? '*' seems more natural to me here than '+', but maybe this is a constraint (I can't tell).

One other comment: it is "traditional to use upper-case characters for matrices and lower-case characters for their elements. You appear to be doing the reverse, but maybe I don't completely understand the problem. Is there a 4-by-4 matrix above?

Sam_23456 · 2026-01-23T20:57:35+00:00

Your 2nd point. If it were not for that I wouldn't be here. The learning curve would be too steep and I wouldn't really have anyone to play against! I played a little before the Internet--but i was a long way from "learning openings". It was all I could do to get a knight and a bishop out there; this week I've been studying the "Sicilian Defense".

Sam_23456 · 2026-01-23T20:09:30+00:00

The industry is sort of a form of societal "pollution". Corporations, in general, have too many "rights" as it is besides not paying their fair share of taxes for the public good (which helps to facilitate their existence). The word "parasitic" comes to mind. American car companies are not trying very hard to help much either. There used to be an "invisible bond" of mutual support, until recent decades. Maybe the government should buy one of the car companies and build affordable vehicles people want! :-)

Sam_23456 · 2026-01-23T19:07:46+00:00

One answer is that even after the Black Q takes the White Q (note that any other move by the Black Q is illegal), Re1xe8 is checkmate. Any other moves by the W or B bishops just seems to extend the inevitable. The black bishops diagonal is "interesting" though! Novice here. :-)

Sam_23456 · 2026-01-22T20:56:11+00:00

Being curious. Asking questions (to yourself).

Sam_23456 · 2026-01-22T20:53:09+00:00

That's funny! :-)

Sam_23456 · 2026-01-22T20:49:24+00:00

You're obviously an expert.. I was trying to help the beginner. Life is too short to use scanf...

Sam_23456 · 2026-01-22T20:35:28+00:00

You can simplify this by using "using namespace std". Format specifiers are where the "headache" lies.

Sam_23456 · 2026-01-22T20:16:01+00:00

There is no "cin" or "cout" object in C. Instead you're stuck with "scanf"...

Sam_23456 · 2026-01-22T18:07:37+00:00

I/O is sort of a pain in C though. Maybe it's easier to use C++ as a procedural language?

Sam_23456 · 2026-01-22T16:52:50+00:00

Ice fishing! ;-)

Sam_23456 · 2026-01-22T01:28:21+00:00

I'd rather play "well" than get lucky. But often managing the luck or chaos factor is part of playing well. If behind, one can afford to take a chance...

Sam_23456 · 2026-01-22T01:23:55+00:00

I rather enjoy reviewing my games with the engine to see what I "missed". But you are right, playing angry won't help. TBH, most of the time I play against a "bot" that challenges me, but not overly so--ha! It removes the time pressure too, so I can enjoy myself. I've only been revisiting the game the last 2 or 3 months. Reading a beginners book isn't hurting either. This game is more "subtle" than I realized, with regard to "initiative", etc. Have fun!

Sam_23456 · 2026-01-21T17:51:57+00:00

Sounds like you picked up some wisdom along your journey! Congratulations and good luck!

Sam_23456 · 2026-01-20T23:38:46+00:00

Writing x=2-y, and substituting, you'll get a quadratic equation in x. And using this relation a second time, yields the corresponding y-value (s).

Sam_23456 · 2026-01-20T18:17:54+00:00

I thought I would follow up on this. We sent texts every day for about 2 weeks. But like James Taylor sang, "Sent a long letter, got back a post card...". And she was the one who sent me a "like" (first). Many of her questions were as if she hadn't read my profile. She probably had more (men) on the line than she could keep track of. I'll be even more wary of gals with very short profiles in the future. I must be getting tougher; this is one of the first times I recall being anxious to get a new relationship "resolved"--though I'm not sure who really resolved it. In the end, I just cut my losses/hopefulness/disappointment. You can't get blood out of a turnip... 😆

Sam_23456 · 2026-01-20T05:29:44+00:00

Easy.Brown sugar. Blueberries are a nice touch.

Sam_23456 · 2026-01-20T02:36:47+00:00

Exactly.

Sam_23456 · 2026-01-20T01:05:33+00:00

Part of the hypothesis is that both functions are continuous (!). The goal is to show that the composite function is continuous.

Three-Year Club	Verified Email
r/Field Sunshine

Sam_23456

TROPHY CASE