Тёмный

Dimension of the null space or nullity | Vectors and spaces | Linear Algebra | Khan Academy 

Khan Academy
Подписаться 8 млн
Просмотров 359 тыс.
50% 1

Dimension of the Null Space or Nullity
Watch the next lesson: www.khanacademy.org/math/line...
Missed the previous lesson?
www.khanacademy.org/math/line...
Linear Algebra on Khan Academy: Have you ever wondered what the difference is between speed and velocity? Ever try to visualize in four dimensions or six or seven? Linear algebra describes things in two dimensions, but many of the concepts can be extended into three, four or more. Linear algebra implies two dimensional reasoning, however, the concepts covered in linear algebra provide the basis for multi-dimensional representations of mathematical reasoning. Matrices, vectors, vector spaces, transformations, eigenvectors/values all help us to visualize and understand multi dimensional concepts. This is an advanced course normally taken by science or engineering majors after taking at least two semesters of calculus (although calculus really isn't a prereq) so don't confuse this with regular high school algebra.
About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.
For free. For everyone. Forever. #YouCanLearnAnything
Subscribe to KhanAcademy’s Linear Algebra channel:: / channel
Subscribe to KhanAcademy: ru-vid.com_...

Опубликовано:

 

17 окт 2009

Поделиться:

Ссылка:

Скачать:

Готовим ссылку...

Добавить в:

Мой плейлист
Посмотреть позже
Комментарии : 68   
@Peachereis
@Peachereis 11 лет назад
skipped whole 6 month classes watch all videos . passed
@JTX8000
@JTX8000 7 лет назад
11:40 for Dimension of Null space, you're welcome
@DannyzReviews
@DannyzReviews 10 лет назад
This guys is the best. But let's face it if universities and colleges could hire professors like this guy who can "teach" a concept and "explain" thoroughly then people would not even have to resort to watching his videos as last minute life savers before a test or exam. Just because someone has a PHD in a subject does not necessarily mean they can teach it. They might be a complete expert and genius in that subject but getting other people to learn it and teaching it to them is a completely different story. The institutes should look at Khan's videos as an example how a great teacher should explain concepts and questions to someone rather than looking at whether they have got a PHD or doctorate in a course.
@rwarzor
@rwarzor 9 лет назад
A lot of those teachers with PhDs are being paid by the college to do research, teaching is their secondary profession. Research brings in big money in grants and publicity to the universities, so they hire smart people who can conduct research
@DannyzReviews
@DannyzReviews 7 лет назад
Haha, didn't think I'd be returning to a 3 year old comment. To be honest, I am also to blame for my lack of incompetence. I procrastinated and would even skip some classes which led to me being in a state where I would have to watch these last minute videos online. I still stand by what I said back then though. treasy​ brought up a good point a lot of profs are actually at institutions for research as their primary job. I had one prof who's lectures were pretty meaningless, but he had contributed a truck load to the university's research. I wrote that comment because I was just really frustrated and was just venting when I should have been studying LOL
@ThinkPositive00
@ThinkPositive00 10 лет назад
Why can't every lecturer explain as clearly and simply as this?
@Yadinma
@Yadinma 10 лет назад
don't u think thats like asking, why cant every basketball player shoot free throws.....
@SomethingSoOriginal
@SomethingSoOriginal 12 лет назад
Not just vaguely useful, EXTREMELY useful.
@vikasutube100
@vikasutube100 7 лет назад
God bless you! The tutorial was amazing!
@GodsOfMW2
@GodsOfMW2 6 лет назад
Love you Sal. Your videos make me look like some sort of super genius in class!
@901help2
@901help2 8 лет назад
Vaguely useful? are you kidding me, thus was great! Thanks for the help Sal!
@Waranle
@Waranle 15 лет назад
You make it so clear. Thank you
@musabahmed3341
@musabahmed3341 2 года назад
Khan for president!!!! 2022
@junkeychan
@junkeychan 12 лет назад
I come listen to this guys voice and all my stress about up coming exam goes away.
@Jef11235
@Jef11235 13 лет назад
Thanks so much, this is EXACTLY what i needed! :D
@uolwass
@uolwass 13 лет назад
absolutely amazing!!! u are a genius, thanks sooooo much
@UltramanII
@UltramanII 13 лет назад
Thanks guy you just saved me from my mid-term!
@basmaal-ghali9174
@basmaal-ghali9174 8 лет назад
Useful... thank you..
@faisaltg14
@faisaltg14 8 лет назад
thank you very much sir , i have final exam in this after one hour you really explained everything for me better than that one we called prof in our college
@yousef.al-assaf
@yousef.al-assaf 7 лет назад
faisal alfaisal كيف كان الامتحان 😂
@johndafish7829
@johndafish7829 10 лет назад
Thank you so much man!!!! You are awesome!
@spsorn5433
@spsorn5433 Год назад
Thank you so much. I love your explanation.
@bhuwandwivedi513
@bhuwandwivedi513 8 лет назад
thanks it helps a lot
@industrialdonut7681
@industrialdonut7681 5 лет назад
Jesus christ that ending "Anyway hope you found that, vaguely useful" LOL
@katlegomalesa5907
@katlegomalesa5907 9 лет назад
perfect!!!
@KingRobbStark
@KingRobbStark 15 лет назад
Dude, awesome.
@tuyetlan888
@tuyetlan888 13 лет назад
Hi there, I would like to know if I did exactly like you did in the video, except I put in row echelon form instead of a row reduced echelon form. Would I still be able to get the right answer?
@mastercgmr
@mastercgmr 13 лет назад
Thank you sr!
@A-003
@A-003 14 лет назад
A thank you would not be enough . . . I dont know wat to say God Bless You
@jstdun
@jstdun 11 лет назад
Damn this was really helpful.
@Car1ll
@Car1ll 13 лет назад
Doesn't this mean that the dimension of A is equal to the number of collumns minus the number of rows of A. Since the reduced row echelon form will allways contain a number of pivots equal to the number of rows?
@zhijieli12
@zhijieli12 Год назад
verrryyyy verryy useful !!!!!!
@twmzzang
@twmzzang 11 лет назад
so good
@wadiczka
@wadiczka 12 лет назад
Amazing job, trying to get ready for linear algebra exam tomorrow.
@antonioalonso5831
@antonioalonso5831 4 года назад
wadiczka How’d it go? Lol
@lemyul
@lemyul 3 года назад
ty
@HariHaran-sl1pg
@HariHaran-sl1pg Год назад
God Bless..
@Robin-pc3jf
@Robin-pc3jf 5 лет назад
Excellent video, though why does the calculation for nullspace start with B but end with A?
@pojorobo1
@pojorobo1 11 лет назад
i have a test in 20 minutes and his videos saved my life
@justinv3
@justinv3 15 лет назад
yup
@sachinduhan3022
@sachinduhan3022 5 лет назад
i wish i can hug uh for ur help
@yanyancui1601
@yanyancui1601 7 лет назад
what if the free variable is not linearly independent?
@KiDFRANKKK
@KiDFRANKKK 12 лет назад
Sick
@realvideosrv1879
@realvideosrv1879 3 года назад
I cant find this complete playlist? Please link anyone? :,(
@genericusername337
@genericusername337 9 лет назад
your handwriting is just like mine!
@codex8538
@codex8538 3 года назад
are the vectors associated with each free variable linearly independent always?
@oneinabillion654
@oneinabillion654 3 года назад
Yes because only that vector associated with the free variable has a 1 in it, whereas it is 0 in the other vectors. So these vectors are always linearly independent after rref since theres no linear combination to represent that "1"
@TheGreatSpanski
@TheGreatSpanski 11 лет назад
Jeeeez what snoozzzzeefest. #YAAAAWWWWWNNNN
@sanmvegs1641
@sanmvegs1641 6 лет назад
Let me ask you a question... is number of non pivot columns the nullity of a matrix and number of pivot columns is the rank of the matrix?
@comtrang
@comtrang 11 лет назад
When the pen hovers closely above the tablet, the mouse is responsive. You don't have to be in contact with it. I use one for Photoshop and that's how mine works.
@WouterNed
@WouterNed 11 лет назад
Then how does he move the pointer around without writing?
@whitesanity4965
@whitesanity4965 4 года назад
luv ya m8
@applecider98
@applecider98 11 лет назад
Teach at my school please???
@leon-lm7uf
@leon-lm7uf 3 года назад
why is my linear algebra class not using matrices--
@vabs9211
@vabs9211 14 лет назад
thx mate..u saved me from failing maths.....lolz
@darlenemontesano3214
@darlenemontesano3214 6 лет назад
how are x2, x4, x5 free variables?
@GodsOfMW2
@GodsOfMW2 6 лет назад
If you look at the columns of the rref matrix, they do not contains any pivot ones. So if you were to expand the rref matrix, the free variables are the ones that appear in both equations.
@howtoguro
@howtoguro 6 лет назад
It actually doesn't need to be in RREF btw. REF will work better since it's a time saver. Row eschelon form is good enough because the numbers will change but the pivots will not. Since the rank-nullity theorem is dealing strictly with the # of pivots col and # of non-pivots col
@nickchi8723
@nickchi8723 2 года назад
basically the number of free varible in the matrix is the dimension of the null space. Dude why must linear algebra has so many terms. nullity = dimension of null space = numberof free verible in rref. Spend 10 min just want to know this and is at the last part of this video....
@srockerrr
@srockerrr 5 лет назад
God I love you.
@comtrang
@comtrang 12 лет назад
I'm pretty sure he uses a USB tablet to do these
@bensher2291
@bensher2291 7 лет назад
I wanna kiss you right on the fuckin mouth Mr. Khan Academy
@user-lb1fl7sh8m
@user-lb1fl7sh8m 7 лет назад
beast mode!!
@6124279
@6124279 11 лет назад
Hes so smart, not even funny
Далее
PORTAL SPAMMER🤬🤬🤬| Doge Gaming
00:19
Просмотров 2 млн
Symmetrical face⁉️🤔 #beauty
00:15
Просмотров 4 млн
Linear Algebra - Lecture 28 - Null Space of a Matrix
13:03
Nullspace Column Space and Rank
20:59
Просмотров 81 тыс.
PORTAL SPAMMER🤬🤬🤬| Doge Gaming
00:19
Просмотров 2 млн