Equation for parabola from focus and directrix | Conic sections | Algebra II | Khan Academy

Поделиться
HTML-код
  • Опубликовано: 9 ноя 2024

Комментарии • 71

  • @lee_voug8357
    @lee_voug8357 7 лет назад +193

    Because of this parabola I lost my childhood and teenage days

    • @saedcruzreyes5092
      @saedcruzreyes5092 4 года назад +2

      WHY? xD

    • @DarthCrustyYT
      @DarthCrustyYT 3 года назад

      @@saedcruzreyes5092 the first video in this series was uploaded 12 years ago to the day I’m writing this and this video came out 6 years later

  • @ryannmunoz7136
    @ryannmunoz7136 7 лет назад +37

    Everytime I struggle with my algebra, I come here. I do online school so it's hard to move forward when I'm stuck without my teacher getting back to me (especially since I'm a night owl. I normally have to wait until the following day). Thank you! I'm bad with numbers but when I watch these videos they (sort of) make sense.

    • @srutishaw6115
      @srutishaw6115 7 лет назад

      Ryann Elizabeth
      Same here. But i m not a online student.

  • @dhruvkhandelwal.
    @dhruvkhandelwal. 5 лет назад +46

    5:21
    **Right side of the screen exists**
    Sal: it's free real estate

    • @Brandon-xm4mp
      @Brandon-xm4mp 4 года назад +2

      thats when you know that sal loves realestate

    • @zionj104
      @zionj104 4 года назад +2

      Dang it, you beat me to it

  • @kellacanb
    @kellacanb 8 лет назад +109

    "Hairy algebra" he says.

    • @davisjohn-d6h
      @davisjohn-d6h 5 лет назад +4

      I like my problems nice and hairy

  • @NoahCartee
    @NoahCartee 6 лет назад +43

    when your teacher gives you a question on a test that he has never covered...

  • @florencecuomo
    @florencecuomo 7 лет назад +49

    "hairy algebra"
    can we just

  • @charmendro
    @charmendro 5 лет назад +3

    5:20 "Let me give myself a little bit real estate over here" lol

  • @amazingunseen681
    @amazingunseen681 5 лет назад +1

    Thanks Salman khan to create this Educational Organization!

  • @ryanio123
    @ryanio123 6 лет назад +5

    Really fantastic Sal. Thank you so much.

  • @甘木-m5r
    @甘木-m5r 6 лет назад +6

    Define childhood ..... do I remember parabolas from my childhood? ✨📚🍨🍉

  • @nikhilverma4976
    @nikhilverma4976 8 лет назад +4

    Thank you! I was in need of such a video for computing voronoi diagrams in my project

  • @GiuseppeLospalluto
    @GiuseppeLospalluto 9 лет назад +5

    Thank you so much man ! You are fantastic

  • @fjkldhakljf
    @fjkldhakljf 5 лет назад +2

    Thanks I will just memorize it

  • @MrDands
    @MrDands 9 лет назад +7

    Fascinating indeed

  • @yomahadar
    @yomahadar 8 лет назад +4

    Which software do you use to write everything?

  • @sarahmotherway3410
    @sarahmotherway3410 5 лет назад +11

    " Hairy algebra" *Shivers*

  • @azrielsshadowsinger
    @azrielsshadowsinger 4 года назад +3

    my brain can’t handle this- what did he just do

  • @lucyheartfilia4607
    @lucyheartfilia4607 6 лет назад +2

    How do I find the equation of the ellipse given only that the the major axis is vertical and the graph passes through the vertex of a parabola?

  • @rdscombatpro5650
    @rdscombatpro5650 9 лет назад +1

    Thank you !!!

  • @alextrezvy6889
    @alextrezvy6889 8 лет назад +3

    The link under (Missed the previous lesson?) is broken.

  • @patrikchristian2071
    @patrikchristian2071 7 лет назад +7

    what if the equation of dirctrix includes 'x' also?

    • @MuDasirYasen
      @MuDasirYasen 6 лет назад

      In that case the principle axis of the parabola will lie at some angle to the x axis and perpendicular to the directrix.

  • @thebiggestobjfan3344
    @thebiggestobjfan3344 9 лет назад +1

    tnx alot !!!!!!!!!!

  • @kevinpena2741
    @kevinpena2741 6 месяцев назад +1

    does anyone have answers to a sheet where we have to solve questions and its called the Focus and Directrix of a Parabola and its a leprechaun drawing on the back

  • @padme8013
    @padme8013 6 лет назад +3

    for what grade is this mainly on? like 8th, 9th, 10th etc.

  • @vusumuzitembe9647
    @vusumuzitembe9647 7 лет назад

    tnx

  • @rishijarral4320
    @rishijarral4320 6 лет назад +1

    love yall

  • @jhukelx
    @jhukelx 7 лет назад +5

    crying and laughing at the same time. lol "hairy algebra" it is!

  • @jimbernabe2289
    @jimbernabe2289 5 лет назад +2

    I watched another video regarding this. It demonstrated another formula (y-k)^2=4p(x-h) Is this formula applicable?

    • @abdullahraja5357
      @abdullahraja5357 5 лет назад +1

      I think that's the case 3 and 4

    • @jeffthevomitguy1178
      @jeffthevomitguy1178 2 года назад

      Yes the difference is the formula he is showing gives the parabola for all possible quadrants. (Y-k)^2=4p(x-h) is used only on horizontal Parabolas and you can reverse it with (x-h)^2=4p(y-k) for vertical ones.

  • @anirudhsoni722
    @anirudhsoni722 8 лет назад

    hey thanks !!

  • @yashsingh963
    @yashsingh963 6 лет назад

    nice

  • @aftabali9372
    @aftabali9372 8 лет назад

    the point in last was the coordinate (x,y) or (a,b)

    • @ayushi6703
      @ayushi6703 4 года назад

      If you ask about focus (1,2) then it is (a,b)

  • @big-pp8582
    @big-pp8582 3 года назад +4

    Take a shot for every “hairy algebra” 😂

  • @FasAntick
    @FasAntick 7 лет назад +2

    how can we find the equation of a hyperbola given the focus and directrix

    • @highlights9175
      @highlights9175 Год назад +1

      commenting on 6year old comment
      sir how's life going?

  • @yourroyalhighness6297
    @yourroyalhighness6297 6 лет назад +2

    "It looks really hairy." HAHAHA

  • @kristophercloud2567
    @kristophercloud2567 6 лет назад

    How do we find the focus or the directrix when the vertex is (4,0) and solving for y=? I can’t find anywhere that answers this. My question is to find if there is a minimum or maximum of the equation y=(x+4)squared.

  • @joshua8704
    @joshua8704 5 лет назад +1

    THE PAIN!!

  • @tutstorial8474
    @tutstorial8474 3 года назад +1

    isn't that supposed to be
    a - x ?

  • @Gabriel-nf5zt
    @Gabriel-nf5zt 6 лет назад

    hola que tal, como les va

  • @MuhammadBilal-hm4gy
    @MuhammadBilal-hm4gy 5 лет назад

    what if directrix is x = a

  • @brittknee3884
    @brittknee3884 5 лет назад +1

    I’m a little stupid so I’d like to know how you got “-2yk”

    • @ayushi6703
      @ayushi6703 4 года назад

      As you can see (y-k)^2 =y^2+k^2-2yk , it's just a simple expanding formula

  • @kellacanb
    @kellacanb 8 лет назад +5

    That formula applies to ALL parabolas?

    • @JM-lh8rl
      @JM-lh8rl 8 лет назад +1

      Kella Boiarddi Yes

  • @alexmisra6690
    @alexmisra6690 4 года назад +3

    This makes no sense

  • @smath82
    @smath82 5 лет назад

    The directrix cannot be y=k since k is the why coordinate of the vertex >_

  • @danielbugtong6795
    @danielbugtong6795 6 лет назад

    y-k then y=k so it means its 0?

  • @tungeshnaidu4569
    @tungeshnaidu4569 4 года назад

    Shouldn't it be (a-x)2+(b-y)2 instead of (x-a)2+(y-b)2

    • @ayushi6703
      @ayushi6703 4 года назад

      In both cases answer will be same as it contains square .

    • @tungeshnaidu4569
      @tungeshnaidu4569 4 года назад

      yes, thank you.

  • @jarodtunacao6241
    @jarodtunacao6241 4 года назад

    lumilipad nanaman ang isip ko

  • @experimentoruser9917
    @experimentoruser9917 5 лет назад

    i dare you to prove parabola opens left

  • @BeanSprouts02
    @BeanSprouts02 5 лет назад

    1:29
    What’s the purpose of using the distant formula here?

    • @BeanSprouts02
      @BeanSprouts02 5 лет назад

      2:08
      And what do you mean negative? The final answer will be negative or will the y variable be the negative variable instead of the x variable?

  • @mrspumpkin6756
    @mrspumpkin6756 6 лет назад +2

    not helpful

  • @isabellacuadras4373
    @isabellacuadras4373 6 лет назад +7

    Hate math!!!!