Lec 8 | MIT 18.06 Linear Algebra, Spring 2005

[AntoMelta]

Good, I like that you share this video Solving Ax = b: Row Reduced Form R., I wish success always

[willamricard]

Nice Video Solving Ax = b: Row Reduced Form R That You Share , So Very Nice Thanks You

[imegatrone]

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[bundawartini]

Your Video Is Very Useful Sharing olving Ax = b: Row Reduced Form R.

[dagarciawmedu]

24:05 "...it's been SHIFTED..." LMAO. Prof. S. must have been thinking, "How can I have made such dumb mistake (23:57 '...it's a subspace...')"

[TaliaRebecasj604]

hmz bin so lieb

[agapitoflores001]

He's brilliant. But observe, most mathematicians have poor handwriting.

[LnX53]

@agapitoflores001 poor? you should see the doctors

[akhil089]

thanks professor strang



[hypnoticpoisons]

So I have to draw a 4-D picture on this MIT cheap balckboard - Einstein could do it..:D

[asam175]

very useful !!!!!!!!

[blackrobe2007]

how did he find that b = [1 , 5 , 6] at 06:03.. is there a systematic way to do it ? or just guess?

[mphmm]

@blackrobe2007

IM not 100% sure but my prof usually did things like this. He just used values that fit the condition so he could proceed.

[blackrobe2007]

@mphmm that sucks...how are we supposed to get those..by guessing?

[HelloIAmDaniel]

@blackrobe2007 get got [1,5,6] from the fact that he had the condition b3-b1-b2=0 which [1,5,6] satisfies 6-1-5=0 he could equally have chosen anything that satisfied this b3=b1+b2 if he took b3=10 and b1=3 (he could have picked any number he wanted) then; 10=3+b2 b2=7 then when he had [b1,b2-2b1,b3-b2-b1] he would get [3,7-6,10-3-7] which would give him [3,1,0] exactly what he got when chosing b=[1,5,6]

[pedroissler]

@blackrobe2007 same issue here, he seems to just throw some stuff, without proper proof :s

[HelloIAmDaniel]

@pedroissler

read my comment below, I said where get got it from

[okonkwo289]

nice proof better than my maths prof

[buzzingbear]

I want to use that fat chalk on that big blackboard ;P

[buzzingbear]

If I were a student in that class, at the end of class I would always thank him after he says "Thanks!"

[LukieRawr]

It's so weird these videos are from 1999..

I was in elementary school learning the multiplication table in 1999.. and now I'm using these lectures to help my pass my University midterms.. woah

[sarocampisi]

Thank you Prof. You r Cool !

[SuperTuringMachine]

24:03 "it's like a subspace, but it's been SHIFTED!!!!"

lolwtf?

[ChristenGC]

what im I saying!! Its not a sub space! Its bean shiftet!!

he totally twitches when he says it. its great :D

great teacher by the way :)

[roombaba]

21:37 MIT should totally build a 4d blackboard

[eroicawu]

"We need an example here..Let me create an example", He totally doesn't need the text book. aha

[rordulu]

it was really funny when he saw his mistake :D:D

[deathbystarship]

lol 24:03 - 24:06

but it's been SHIFTEDAGREAG

[IamJacksColon4]

his zeros look like 3eros

[ebsanu]

Great lecturer, mediocre author.

[MrSystemVI]

Thank you MIT and Prof. Gilbert Strang.

I am learning Linear Algebra from you. I am very much grateful to you for having shared these great lectures to the world, and giving other self-learners in the world opportunities of learning from the best.

Thank you very much!

[AutodidacticPhd]

"...giving other self-learners in the world opportunities of learning from the best."

True enough. Of course, it would also be nice if they would release a few more lecture series from other subjects. I'm spoiled now... it is so frustrating walking into a course without already knowing it forward and back.

;)

[Manolis090]

True enough, I would love some lectures in econometrics.

[Mathematics215]

Lol wow... nosojdjos what a great comment.

1) If its only 10000 times faster thats a sad computer!!!

2) A computer can multiply and exponentiate things that would take humans years to do but we still teach multiplication to kids?

3) Concepts like this are fundamental if you actually DO write programs for computing solutions or largest eigenvalues of very large matrices. (on the order of 10^6 by 10^6 or greater, well in those cases you need a lot more tricks but the principle is the same)

[JimmyTheGreek2000]

Well, this is a lecture to people who have no idea what a vector, Matrix or Eigenvalue is!

They have to learn first before using the PC to solve problems.

If not, it is GIGO!

[JimmyTheGreek2000]

It is human to make an error.

It takes a computer to screw things!

[urimv]

yeah but who do you think comes up with the programs that solve this stuff in a split second? even though solving a matrix may be an exercise in futility nowadays, it is still vital to know how to do it.