Conic Sections: Intro to Circles

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  • Опубліковано 16 гру 2024

КОМЕНТАРІ • 124

  • @flip2shoot567
    @flip2shoot567 9 років тому +30

    my math teach flies through the math lessons and i am soo glad to have found this guy, the things sal teaches just clicks in my head

  • @NaturePill1
    @NaturePill1 8 років тому +188

    Khanic sections.

  • @dnmn8r
    @dnmn8r 13 років тому +40

    "You'd be almost right, but you'd be exactly the opposite of the correct answer"

  • @esvw1986
    @esvw1986 6 років тому +18

    this guy is probably an engineer: "It's supposed to be centered at zero, but that's good enough"

  • @minfei.
    @minfei. 4 роки тому +2

    11 years ago and still helpful. Thank you.

  • @yunogasai5830
    @yunogasai5830 5 років тому +85

    Any stem student here?😂

  • @MrHjld
    @MrHjld 12 років тому

    i love 6:00 because this guy actually takes us the time to explain why its not (-1,2). the text book just tells us how to do it, not why reversing the sign on the values works.

  • @Leonar12345
    @Leonar12345 13 років тому +10

    "you'd be almost right except you'd be exactly opposite the right answer" lmao please never stop making vids

  • @mariomaruf
    @mariomaruf 14 років тому +2

    I used your videos to help me pass a test to take Calculus in freshman year.

  • @naughtydevil02
    @naughtydevil02 14 років тому +2

    thank you so much i felt so left behind wheni had no idea about conic in my precalculus class...and so close to finals u really helped me out a lot :)

  • @6cldcs
    @6cldcs 10 років тому +49

    "Some Algebra classes like to complicate things by SHIFTING THE CIRCLE" Uhh...can someone say amen?

    • @fsandlksndkasd
      @fsandlksndkasd 10 років тому +6

      amen!
      it would be nice if the calculations were a easy as just "shifting"

  • @AshleyWeill
    @AshleyWeill 9 років тому +3

    Oh my gosh I'm reviewing for my final and this is so helpful to refresh my memory. I'm so glad I found this is very helpful!!!

  • @MorganAMason
    @MorganAMason 12 років тому +1

    this is so helpful!! I'm studying for my ACT and your videos are a life saver for geometry!

  • @norine362
    @norine362 7 років тому +11

    geez, i understand you more than i understand my math teacher.

  • @invisiblebutterfly6
    @invisiblebutterfly6 12 років тому +1

    Hey Sal, thanks for the video! :)
    If you hold shift on the keyboard while drawing shapes it will keep the shape uniform, i.e. you can only draw circles, or squares depending on the tool you use. :)

  • @kenchinr.labado4126
    @kenchinr.labado4126 Рік тому

    13 years ago still helpful.

  • @ghostbusterz
    @ghostbusterz 9 років тому +5

    Where is this video on Khan Academy? It doesn't seem to be in the Conic Sections category of Algebra 2 under Circles.

  • @stix5078
    @stix5078 7 років тому +1

    For the formula at 0:40 couldn't the formula be simplified by taking out the squared EX: x+y=r instead of all those squared's?

    • @nehaljain8721
      @nehaljain8721 6 років тому +1

      STIX you cannot cut the squares unless it is (x+y)^2 = r^2

  • @onehair190
    @onehair190 5 років тому +1

    How did the center turn into positive 1 and negative 2 while inside the equation it is vice versa

  • @myfatchild17
    @myfatchild17 9 років тому +1

    man i got to say you have saved my ass in for college

  • @scion544
    @scion544 14 років тому +1

    @idster7 Of course x and y aren't 0. They're not even on the function. You're assigning two values. In a x-y function one variable is dependent upon another. So if y=x+1, you can't say because x is 0 and y is 0 the function wouldn't work.

  • @beastquit0176
    @beastquit0176 5 років тому

    I have a exam tomorrow so i need to watch this.

  • @markcuanas5283
    @markcuanas5283 6 років тому +1

    This helps me a lot 👏

  • @grantwahlberg4977
    @grantwahlberg4977 6 років тому +3

    THE BEEPING AGHHHHHHHHHHH I CANT TAKE IT

  • @zeusake_
    @zeusake_ 5 років тому

    Best video ever, totally prepared me 😉

  • @asteroides8204
    @asteroides8204 11 років тому +1

    i love your voice! ....and your teaching of course ahaha

  • @JuanPablo-fq8tl
    @JuanPablo-fq8tl 6 років тому +15

    Cause of Death: Math

  • @cinquain0
    @cinquain0 6 років тому +1

    That video was fire!

  • @ad2181
    @ad2181 15 років тому

    Sal,
    Your back!

  • @daanush468
    @daanush468 8 років тому

    Distance formula -> (x-x2)^2 + (y-y2)^2 = r^2. If x2 = 1 and y2 = -2, you get (x-1)^2 + (y+2)^2 = r^2. Simple.

    • @Cindy99765
      @Cindy99765 8 років тому

      How about..
      d= \|(x2-x1) + (y2-y1)

    • @daanush468
      @daanush468 8 років тому

      We will have to take the under root of the RHS in that case, I believe, it might apply to this current situation that we have (I have forgotten what it is), but it should be d = [(x-x2)^2 + (y-y2)^2]^1/2

  • @PurpleTwilightStar
    @PurpleTwilightStar 14 років тому

    Can someone please tell me the center of the last circle spoken about because my sound doesn't work and i cannot make heads or tails of this without the sound

  • @scion544
    @scion544 14 років тому

    Hey, do you use a mouse or like a pen to write this stuff out? An electric pen of course..

  • @aeroisntliving7849
    @aeroisntliving7849 4 роки тому

    Anyone watching this because modules aren't enough to learn this lesson?

  • @FunChemistryDemos
    @FunChemistryDemos 12 років тому

    8:42 If the formula of the circle is C: (X - Xo)^2 + (Y - Yo)^2 = r^2 then the center's coordinates are (Xo, Yo)

  • @lofiryhthm
    @lofiryhthm 4 роки тому

    Hi what app did you use for your video?

  • @rabiasher
    @rabiasher 9 років тому

    anyone know how to graph it on a computer, or any program. Need it for a school assignment

    • @MrSupercrazyllama
      @MrSupercrazyllama 9 років тому +1

      Abdullah Sher i know that this is late, but for future reference i use a program called geogebra

  • @redkees5
    @redkees5 12 років тому +1

    aside from the wheel, what are other real world applications of the circle?

  • @lwreltteratgmail
    @lwreltteratgmail 12 років тому

    how about the world as an infinite amount of circles (actually ellipsoids) turned around the rotation pole?

  • @deaththompson
    @deaththompson 12 років тому

    Hahahaha "And you'd be almost right except you'd be exactly, uh, the opposite of the correct answer" Sal is hilarious

  • @krispyy3994
    @krispyy3994 5 років тому +1

    How does (X-1) ^2 + (Y+2)^2 = 3^2 and its center is (1,-2) ?? Is it given to change the sign??
    I thought it was (1,4) lol hahaha

    • @renabelesayco7823
      @renabelesayco7823 5 років тому

      the sign should be change when you're going to plotnit

  • @Jaszleemin
    @Jaszleemin 8 років тому

    what software you use please answer asap...

  • @Zion_fire
    @Zion_fire 9 місяців тому +1

    R we squared?

  • @nairks5082
    @nairks5082 10 років тому

    in the end as we wanted (y+2)=4
    why couldn't the value of "y" be -4 ?

    • @lolzomgz1337
      @lolzomgz1337 9 років тому +3

      Because then you'd have -4+2 = 4
      2=8
      or
      -2=4
      ...

  • @cutiesweetsmile
    @cutiesweetsmile 11 років тому

    how to determine the equation of a circle passing thru different points? I know the point has to be substituted in the standard form but I don't know how to continue solving after substitution. I need help :(

  • @MattTrainorHD
    @MattTrainorHD 9 років тому +92

    i honestly hate math

    • @morganhatch1513
      @morganhatch1513 9 років тому +4

      +MattTrainor your gonna have a bad time

    • @FieryPheanix
      @FieryPheanix 9 років тому +6

      Math is eveywhere... If you hate math have fun trying to get a well paid job

    • @daanush468
      @daanush468 8 років тому +9

      +Pratyush Srivastava become a singer, celeb, artist (a great one), or a TV show writer, typical thinking.

    • @levi4328
      @levi4328 8 років тому +6

      or run for president.

    • @hanumanaska292
      @hanumanaska292 8 років тому +1

      MattTrainor, then I honestly hate you.😡

  • @user-md9hd4ps5m
    @user-md9hd4ps5m 4 роки тому +2

    im an IT student and idk what the heck im doing here

  • @AnomalousAppendages
    @AnomalousAppendages 14 років тому

    Ah, x^2 + y^2 = 1 is a circle with radius 1, becomes pretty obvious once you see it from the trigonometric unit circle since cos^2 x + sin^2 x = 1 :D

  • @Raiyun166
    @Raiyun166 15 років тому

    I only wish this cane out last year when I had to do this. :(

  • @CstriderNNS
    @CstriderNNS 9 років тому +5

    "you would be almost write , except you would be exactly opposite of the correct answer" ................................wha ? lol

  • @idster7
    @idster7 15 років тому

    i think this is the first of a hundred sal videos i've watched that i haven't really gotten. i don't understand the equation x-squared plus y-squared equals 9. how could x be 0 and y be 0? that wouldn't equal 9.

  • @mesinajohncarlo9281
    @mesinajohncarlo9281 6 років тому

    He looks charming when he teach math😂

  • @AhmedAC561
    @AhmedAC561 7 років тому

    Thank you.

  • @matthewezekieljr.9304
    @matthewezekieljr.9304 4 роки тому

    Why was it *-1,2* tho

  • @el6478
    @el6478 12 років тому

    What about his back?

  • @princessana2000
    @princessana2000 4 роки тому

    anyone reviewing bc of quarantine?

  • @albertocedeno5490
    @albertocedeno5490 3 роки тому +1

    😎🎖️🤩🏆☺️

  • @scoutescudero4770
    @scoutescudero4770 5 років тому

    What is circle?

  • @Rayman304
    @Rayman304 15 років тому +1

    1st comment!!
    awesome video

  • @aceofgabriels3448
    @aceofgabriels3448 5 років тому

    why no audio

  • @rishaltauro511
    @rishaltauro511 8 років тому

    Wen diameter is 9. Den how is the radius 3?

    • @qasimasif1492
      @qasimasif1492 8 років тому +2

      Rishal Tauro it isn't diameter that's 9. It's radius squared that's 9. You simply take under root of 9 to get radius. Which is 3

  • @Olaoo99
    @Olaoo99 12 років тому

    THANKS

  • @mvagos6
    @mvagos6 15 років тому

    thanks bro

  • @remotecontrol2355
    @remotecontrol2355 4 роки тому

    3:08

  • @intindse
    @intindse 12 років тому

    his back?

  • @ahmedmahamadmahmood
    @ahmedmahamadmahmood 12 років тому

    Sal !!! iam ready to challenge you that you could make it much more shorter !!!!

  • @qweasdzxc390
    @qweasdzxc390 8 років тому

    khan academy is goat

  • @pinkrules379
    @pinkrules379 11 років тому +3

    You talk like the Doctor

  • @rayneangelique784
    @rayneangelique784 4 роки тому +1

    STEM PA MGA TANGA!!🤣🤣

  • @yuukihanabi4758
    @yuukihanabi4758 4 роки тому

    October 5 na bukas welp

  • @shaysimpson734
    @shaysimpson734 4 роки тому

    Can't understand anything huhu

  • @ljk20001
    @ljk20001 11 років тому

    translation of a circle ....

  • @hello-xk9ze
    @hello-xk9ze 7 років тому +3

    I hate Pre-Calculus.

  • @amadodiego88
    @amadodiego88 12 років тому

    *you're

  • @sabingharti6218
    @sabingharti6218 10 років тому

    hiiiiiiiiiiiii

  • @hedonism13
    @hedonism13 13 років тому

    @dnmn8r
    Was just gonna comment that...

  • @RamAvtar-mt9jh
    @RamAvtar-mt9jh 5 років тому

    Well it is a low level explanation

  • @jerfbejoc1825
    @jerfbejoc1825 4 роки тому

    Yow stem pss
    Student*

  • @graysonhigh
    @graysonhigh 12 років тому

    Get some friends.