Complex Numbers (part 1)

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  • Опубликовано: 28 дек 2024

Комментарии • 232

  • @TheAlexmercer360batmanfan
    @TheAlexmercer360batmanfan 10 лет назад +68

    This guy really knows how to teach,as in,how to get things inside the most clueless of the heads,I would wager these videos are better than most local tutors you would find in US,some would charge huge money for the iinfo contained in this tiny vid,so Mr.Khan,you have our most dear thanks :)

  • @imapabdou2503
    @imapabdou2503 7 лет назад +320

    Stop scrolling down, and focus on the video.

    • @hindaomar2329
      @hindaomar2329 7 лет назад +9

      BENACHOUR Abdou ok sorry

    • @thyduck7542
      @thyduck7542 6 лет назад +4

      My bad

    • @Teal_.
      @Teal_. 5 лет назад +1

      yea my bad, thanks for looking out for me

    • @numbersletters2920
      @numbersletters2920 5 лет назад +1

      1➗♻️💤🖼🎼❄️😢math classes in university establish myself as career ready.

    • @maramkh1423
      @maramkh1423 3 года назад

      Ok thanks for the warning lol

  • @stephentoenjes108
    @stephentoenjes108 10 лет назад +113

    The most soothing voice on the web.

    • @peihu3201
      @peihu3201 7 лет назад +2

      ikr

    • @shripriyaramanujam8711
      @shripriyaramanujam8711 7 лет назад +2

      Well, second most soothing voice on the Web. There are video recordings of _The Joy of Painting_ by Bob Ross

    • @wiz9203
      @wiz9203 6 лет назад +2

      Most scary voice 😨😨😨😨😨😬😬😱😱

  • @remedyzipcode4603
    @remedyzipcode4603 9 лет назад +17

    My teacher sucks so bad at teaching geometry im glad you do these videos to help people like me

  • @talzO9
    @talzO9 9 лет назад +167

    I wish Khan would re-do these videos in higher quality so they were easier to look at. Still great though!

    • @pebble2259
      @pebble2259 7 лет назад +1

      Is it possible this is a dupe channel fishing for likes?

    • @timtams_6
      @timtams_6 5 лет назад +3

      @@pebble2259 It's a video from 2008. What would you expect?

  • @ApoorvaV
    @ApoorvaV 9 лет назад +15

    I love Khan academy!!!!! Thank you so much for helping me.

  • @harderhscmaths
    @harderhscmaths 12 лет назад +1

    Thank you Sal. You are an inspiration. Through your help I have begun my RUclips videos.
    It was a bit daunting at first but now I am getting into the swing of it. I have watched your style and your relaxed manner has helped enormously. I don't worry as much when I make a mistake and this makes it more enjoyable in the presentation. I believe that we are providing great opportunities for students wh cannot afford textbooks or are too far away from a school. Once again thank you. John Kinny-Lewis

  • @alexbat007
    @alexbat007 11 лет назад +11

    If only all people could teach like this with this sort of homework!

  • @yakmuck
    @yakmuck 16 лет назад

    great videos. College has no mercy for us math deficient distance learning students. These vids are a good resource for the lost.

  • @0riginalrick
    @0riginalrick 14 лет назад +1

    Thank you so much. It makes me wonder why math books and math teachers make it seem so difficult. What I couldn't understand after 3 hours of studying from my mathbook, I now do understand in under 20 minutes watching your video.

  • @jacobnathanielbutler
    @jacobnathanielbutler 11 лет назад +1

    I could save a shitload of money just staying home and watching these videos all day, I would definitely learn more. To bad I have to pay thousands of dollars for a piece of paper with my name on it....

  • @25911454
    @25911454 14 лет назад

    what my tutor coulndnt teach me in a week............sir,u taught me in 10 mins.............thnk u so mch sir......i will surely get gud mrks

  • @كورةبلس1-ث1ظ
    @كورةبلس1-ث1ظ 7 лет назад +11

    I am the son of wounded Syria. We lost our homeland and we still want to learn ... Syria Damascus

  • @danielingvarsson3029
    @danielingvarsson3029 10 лет назад +9

    It works if you fast forward few seconds.

  • @paddaguduru
    @paddaguduru 5 лет назад +1

    Sal's voice is ASMR
    New Bob Ross

  • @victornavarro4285
    @victornavarro4285 11 лет назад +1

    love these kind of videos they explain and make things clear!

    • @franklinmaldonado1949
      @franklinmaldonado1949 5 лет назад +1

      Victor Navarro is greatly help me out and have fun in Florida for the best for🕶️👓🕳️🕳️👢👒

  • @deepaksompurkar2946
    @deepaksompurkar2946 7 лет назад

    namaste and thanks for enriching worlds knowledge through your endeavour

  • @suprgx
    @suprgx Год назад +1

    Legend

  • @mehdijalali2874
    @mehdijalali2874 8 лет назад +3

    We thank for your nice activity of the RUclips

  • @alansmithee419
    @alansmithee419 6 лет назад +4

    2:00. I get annoyed at this too. Imaginary is a terrible name. They're just as valid as any other number. They're just different.

    • @dingdong3021
      @dingdong3021 3 года назад

      Then call them anything you want idiot.

  • @MrAndySickness
    @MrAndySickness 12 лет назад

    Okay so I actually enjoy math to some extent, but this chapter ticks me off.
    And you just made it fun and easy to understand and it was funny. c:
    The dimension thing really helped haha. Thanks dude.

  • @steven1234554321
    @steven1234554321 12 лет назад

    Thanks for the lesson! And for getting me to look up and learn the word monotenous! Such a sick word!

  • @dhritisuresh8131
    @dhritisuresh8131 5 лет назад

    'I dont wanna confuse you' 1:52
    No Sal, you're helping me with my degree

  • @thetrillchemist8555
    @thetrillchemist8555 10 лет назад

    Great explanation totally makes sense! I'm happy to know what I have coming this August !

  • @DecoyProductions
    @DecoyProductions 6 лет назад

    These videos need to be rerecorded, its been 10 years Sal!

  • @estarossa1847
    @estarossa1847 6 лет назад

    I appreciator your explanation skills

  • @shallowcoder1
    @shallowcoder1 11 лет назад +1

    now why can't all teachers be this good?

  • @labmem004
    @labmem004 8 лет назад

    Thank you for that good lesson. Much love!

  • @energie9966
    @energie9966 8 лет назад

    nice videos. i have another different powerful explanation for complex numbers

  • @pussybag6417
    @pussybag6417 12 лет назад

    You explained this so much better than my college professor ha

  • @richardaiwe1542
    @richardaiwe1542 7 лет назад +1

    Nice work !! Wish i found dis earlier.

  • @MariaDiaz-tg5cn
    @MariaDiaz-tg5cn 12 лет назад

    muy buena tu esplicacion, a pesar de que no hablo tu idioma, entendi, gracias!

  • @mollyalfred7099
    @mollyalfred7099 5 лет назад

    CAPE Inte. Math on Monday... Thanks for the videos!

  • @khodorhajj8386
    @khodorhajj8386 4 года назад

    Very nice lesson

  • @sauri2005
    @sauri2005 14 лет назад

    thank you so much for this. really easy to understand. i hope you were my calc teacher. i was wondering if you have any videos for sinusoidal steady state analysis

  • @DumbNinjaDude
    @DumbNinjaDude 4 года назад

    I had an interesting thought; if you graph the y axis vertically and the x axis horizontally, could you then use the “imaginary” axis perpendicular to that x,y plane and generate functions in all 3 dimensions?

  • @Visualizingmathandphysics
    @Visualizingmathandphysics 12 лет назад

    So just as there is East, West, North and South,
    In maths, there is
    1,i,-1 & -i.
    Hope this helps
    Binnoy.

  • @Underdisc
    @Underdisc 12 лет назад

    I have a suggestion for you Khan. You should make a playlists that separate the curriculum from multiple subjects. One should have all of the Geometry Curriculum, Algebra 2 Curriculum. Pre-Calculus Curriculum, and etc. If you do that, I can skip two years in mathematics.

  • @mariabrader461
    @mariabrader461 6 лет назад

    thank you! probably saved my grade.

  • @muranvya
    @muranvya 15 лет назад

    yo, Sal, u saved me in calculus II, u do
    Calculus III as well? I'm saveeeeed again. U have no idea how happy i was to hear ur voice

  • @Visualizingmathandphysics
    @Visualizingmathandphysics 12 лет назад

    Complex plane was invented to measure rotation, just as a normal x-y plane is used to measure change in size, length, distance etc.
    Binnoy
    Visualizing Maths
    A book beyond Formulas

  • @lucyandljk
    @lucyandljk 12 лет назад

    Watching a productive 10 minute video instead of going to a 50 min lecture :D at home while eating subway :D

  • @thelastvampirehunter
    @thelastvampirehunter 13 лет назад

    This video helped out a lot, thank you!

  • @moctezuma696
    @moctezuma696 10 лет назад +7

    Thanks for that... Mr Khan, could you please tell me what software / e-pen / digital pen you are using. I am looking for user-friendly delivery platform. Thanks in anticipation. Moctezuma

  • @Visualizingmathandphysics
    @Visualizingmathandphysics 12 лет назад

    Complex numbers actually indicate rotation.
    i = rotation by 90 degrees.
    i^2 = rotation by 180 degrees = -1 = negative of that number.
    .
    i^3= rotation by 270 degrees = -i
    i^4 = rotation by 360 degrees =1.
    Rotation by 360 degrees brings the object back to the same position.
    Take any object in your hand and rotate it by 90 degrees 4 times. You will see that it comes back to as it was before rotation.
    There is a whole video dedicated to complex numbers on my channel, if you wish
    Binnoy

  • @protoname_
    @protoname_ 12 лет назад

    Thanks so much! I owe you tons!

  • @dharma6662013
    @dharma6662013 9 лет назад

    This is a great video, but be careful. i^2 = - 1 gives two possible definitions for i because i^2 = - 1 and (- i)^2 = - 1. The custom is to choose i = +\sqrt(- 1). There are really two models for the complex numbers. They are automorphic under conjugation z --> z*.

  • @lawal211
    @lawal211 12 лет назад

    Thank you so much. This was a lot of help.

  • @ChuuliviaHye
    @ChuuliviaHye 11 лет назад

    Wow. You explain this way better than my teacher xD

  • @shiza223
    @shiza223 14 лет назад

    you are a hero!!!

  • @jerome1470
    @jerome1470 13 лет назад

    Thank you for this video! It helped me understand much better a hell lot! :)

  • @danny3640
    @danny3640 5 лет назад

    In 1:25 if we defined I as -1 and we squared it wouldn't it become 1?

    • @negarv6093
      @negarv6093 5 лет назад +1

      Im pretty late but I^2 is defined as -1 not I

  • @issunRyuBlackBelt
    @issunRyuBlackBelt 13 лет назад

    Found this right after my test. Of course.

  • @harderhscmaths
    @harderhscmaths 12 лет назад +1

    I also do complex numbers from past exam papers.

  • @josh-bond97
    @josh-bond97 11 лет назад +1

    Complex numbers........... they sure got that name right

  • @alijahhodgson390
    @alijahhodgson390 6 лет назад

    For those discussing the quality, youtube videos actually slowly degrade in quality over the years and develop some artifacting, which has been proven on a number of occasions. This is most likely caused by the video files being moved from server to server, compressed, copied, or otherwise disturbed over the years since they were initially uploaded.

  • @macmike76
    @macmike76 12 лет назад

    thanks, really helpfull and with subs

  • @Nemanoid
    @Nemanoid 6 лет назад

    what program does he use to explain this?

  • @rajcatchem7942
    @rajcatchem7942 10 лет назад +1

    Find all complex numbers z satisfying z5 = 1 + 2j. How many complex
    numbers satisfy this equation?

  • @Foreveralonecuuuh
    @Foreveralonecuuuh 9 лет назад +10

    I'm so confused

  • @LesIsMoreFilms
    @LesIsMoreFilms 11 лет назад +1

    This is all fine and dandy...but what does this have to do with Batman?

  • @alZiiHardstylez
    @alZiiHardstylez 14 лет назад

    Looking up some hardstyle and I've reached exactly what I had to complete for my tutor.
    Fate?

  • @mosamariamathews3217
    @mosamariamathews3217 7 лет назад

    thank you so much i understand much better

  • @Guitare_picking
    @Guitare_picking 11 лет назад

    would -3i also be a solution of (-9)^(1/2)? because if I square -3i I have -9

  • @Luxcium
    @Luxcium 7 лет назад

    This video is so nice but I am used to a so high level of quality now so the lack of pop filter annoys me so much but hey dont worry for me its still a great teacher and a nice video

  • @Harry0Ron0Hermione
    @Harry0Ron0Hermione 16 лет назад

    Is this for high lvls?

  • @jhonchavez3124
    @jhonchavez3124 9 лет назад

    So all complex numbers do is turn the number into negative or positive?

    • @qbwkp
      @qbwkp 9 лет назад

      No, a complex number consists of a real and a imaginary part
      Bi can also be a complex nimber since the real number can = 0, so bi+0 is still a complex number and vice versa

  • @Gogargoat
    @Gogargoat 11 лет назад

    So a real number is magnitude, and the imaginary part of a complex number is also magnitude, but is orthogonal to the real magnitude?
    When you multiply by an imaginary part, you also rotate the vector 90 degrees pushing it into the other dimension?
    I'm not sure exactly how to say it, but am i understanding this correctly?

    • @WilliamFordRoom340
      @WilliamFordRoom340 10 лет назад

      Gogargoat Yes. If you graph a quadratic equation it makes a parabola; however, the graph of the complex solutions to that same quadratic equation will form a parabola perpendicular to the Cartesian plane.

  • @v3le
    @v3le 7 лет назад

    1:40 I came to the exact point and asked: do the negative numbers really exist ???

  • @toolbass24
    @toolbass24 14 лет назад

    Ty Sal. U sound like the guy from super Mario frustration

  • @SamiWaters5634
    @SamiWaters5634 11 лет назад

    very helpful for review! thanks!

  • @demisous
    @demisous 15 лет назад

    your the best :)

  • @angelicajob
    @angelicajob 11 лет назад +1

    He said "image clear, image clear"

    • @franklinmaldonado1949
      @franklinmaldonado1949 5 лет назад +1

      Angelica Joy Baloloy is the only one who has been ⛑️📿💄🦁🦁

  • @alansmithee419
    @alansmithee419 6 лет назад +1

    Wait. Is i bigger than -i? Is 2i bigger than i? Is there no concept of 'bigger' when it comes to these numbers? I suppose they're all 0+ni meaning they are all 0 with some other value that isn't really 0 but is on the real plane? But then you could say that all real numbers are 0i+n, making my point meaningless. Is it that they are bigger only on the imaginary axis and that real numbers get bigger on the real axis?

    • @douglasstrother6584
      @douglasstrother6584 5 лет назад

      Consider the modulus of a complex number as its size:
      mathworld.wolfram.com/ComplexModulus.html

  • @MrMcVilla
    @MrMcVilla 11 лет назад

    No, root -9 would be 3i. -9= 9i^2, so root -9 is root 9 multiplied by root i^2, which is 3i

  • @fireballBTF69
    @fireballBTF69 11 лет назад

    wouldnt root -9 be 9i? since root -1 is i??? im confused

  • @mynameisnotgirl8184
    @mynameisnotgirl8184 8 лет назад +1

    I wish the writing was consistent. Some 2's looked like 7s, equal signs looked like C's and i's looked like L's.

  • @XDGB97DX
    @XDGB97DX 12 лет назад

    ahh thank you my friend for making that clear to me =)

  • @vijaysinha1069
    @vijaysinha1069 4 года назад

    Complex numbers!!

  • @frostshadow5
    @frostshadow5 13 лет назад

    when he subtracted z1 - z2 why did he get (a-c) PLUS (b-id)i , emphasise on the plus linking the two there

  • @bldubl
    @bldubl 12 лет назад

    Nooice.

  • @NateMan58
    @NateMan58 15 лет назад

    Sweet thanks mate!

  • @ull893
    @ull893 13 лет назад +1

    I dont understand why the college teachers cannot teach like this...they take way too much time, but only end up confusing the students. May be because they get paid too much...!!

  • @martmelee
    @martmelee 14 лет назад

    wow you got some skills with the mouse...LOL

  • @sangeetanurag6537
    @sangeetanurag6537 11 лет назад

    compute
    z= cosa+sina+i(sina-cosa)
    after findind
    t*=a-pi/4
    then what i will do and what will z+?

  • @Perrydiculous
    @Perrydiculous 10 лет назад +6

    Why doesn't this work? I have to go to my calculus resit in an hour :P

    • @reatleatmcpagani4997
      @reatleatmcpagani4997 7 лет назад +1

      when you see this comment from 3 years ago xPPPP
      so how did you do the resit?

  • @ethansegat9713
    @ethansegat9713 7 лет назад +1

    I am new to this. Why does i^2 = -1?

    • @BiscuitZombies
      @BiscuitZombies 7 лет назад +2

      Ethan Segat because i = the square root of 1
      So if you square both sides, i^2 = -1

    • @Suggy08
      @Suggy08 6 лет назад

      It just is. It's like saying why are bananas yellow

    • @alansmithee419
      @alansmithee419 6 лет назад

      @@Suggy08 because its evolutionarily good for them

  • @jirosei8
    @jirosei8 12 лет назад

    what about linear vector spaces?

    • @franklinmaldonado1949
      @franklinmaldonado1949 5 лет назад

      jirosei8 is greatly help you 😎🧘 👤👤 👤🗣️👤👤👤 👤🗣️ is greatly help me with this matter is greatly help you with

  • @feminineessence2007
    @feminineessence2007 7 лет назад

    At which grade do u usually start learning this?

  • @lwreltteratgmail
    @lwreltteratgmail 12 лет назад

    why is this in the first half of algebra? i personally dont have a problem with that but i dont understand this kind of order...

  • @luckylove72
    @luckylove72 12 лет назад

    I don't get this thing. In book CN i defined as ordered pair (x,y) x and y real. Then it defines i as (0,1). It also defines Re(z)=x and Im(z)=y. Then addition and multiplication ....then book writes (x,0)=x plz explain this. I figure out this only Re(z=(x,0))=x But how (x,0)=x??. Soon my exams are from 23rd

  • @GndmMkv
    @GndmMkv 14 лет назад

    i heard that imaginary numbers were to be used in eletricity. respond to me if im right beacuse i dont really remember

  • @frxstrem
    @frxstrem 13 лет назад

    @MilitaryMan006 It is 0.707 + 0.707i, or √(1/2) + √(1/2) i

  • @JoeClawsy
    @JoeClawsy 15 лет назад

    @k0du123
    It's used in electronics and fluid mechanics

  • @wear2whale
    @wear2whale 13 лет назад

    why don't more teachers teach like this?

  • @braidznplaitz
    @braidznplaitz 12 лет назад

    u may check his videos in other languages as well

  • @animyeboah1554
    @animyeboah1554 7 лет назад

    GOOD

  • @Nandine2
    @Nandine2 16 лет назад

    oh my god i love you!

  • @ultimage7
    @ultimage7 15 лет назад

    Lol..
    I just turned 14 a little over a month ago and I'm using this in Pre-Calc (Junior year).

  • @70925007
    @70925007 14 лет назад

    wow ur so smart! how can i be like you??