How to find the focus and directrix of a parabola

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  • เผยแพร่เมื่อ 25 ธ.ค. 2024

ความคิดเห็น • 182

  • @MrPewPews
    @MrPewPews 5 ปีที่แล้ว +517

    Those ppl laughing at the beginning need to appreciate how good of a math teacher they have

    • @ballipatiumapadma3116
      @ballipatiumapadma3116 4 ปีที่แล้ว +3

      Yes

    • @tobyv6087
      @tobyv6087 3 ปีที่แล้ว +44

      yea we all know you cant make a single noise if u have a good teacher

    • @jackphillips3354
      @jackphillips3354 2 ปีที่แล้ว +8

      I know! It’s like with Walter White in the pilot episode.

  • @brianmclogan
    @brianmclogan  11 ปีที่แล้ว +98

    happy to help you understand

    • @kunohs
      @kunohs 11 หลายเดือนก่อน

      thanks!

  • @NightmareTTR
    @NightmareTTR 7 ปีที่แล้ว +217

    I appreciate that you put the problem in the thumbnail so I know what I am getting into, it makes things a lot easier so I don't have to jump from video to video.

    • @brianmclogan
      @brianmclogan  7 ปีที่แล้ว +56

      you are very welcome! It took awhile but thought if I was a student would not want to waste time learning about a problem I already know or not what I am looking for

  • @USAsniper73
    @USAsniper73 11 ปีที่แล้ว +23

    Thank you so much, I missed a week of school and my teacher gave me the notes but he skips steps (it's an honors class) and I couldn't figure it out. I think every teacher should record their lessons like that it would help so much. Thanks again!

    • @brianmclogan
      @brianmclogan  11 ปีที่แล้ว +6

      you are very correct I hope that more teachers follow this because then whatever is specific to your class you can follow

    • @disneyj5380
      @disneyj5380 8 วันที่ผ่านมา

      I freaking hate honors classes they explain nothing like what then they give u a test every 2 seconds

  • @brianmclogan
    @brianmclogan  11 ปีที่แล้ว +17

    When I did the problem I got (x+6)62 = 2(y+2) I will be happy to make a video as I need more examples in my library for these types of problems

    • @AmenaYasserAbdElnabyEbrahimGoh
      @AmenaYasserAbdElnabyEbrahimGoh 10 หลายเดือนก่อน

      how did we know that the parabola would be vertical?

    • @hosam8352
      @hosam8352 7 หลายเดือนก่อน

      @@AmenaYasserAbdElnabyEbrahimGoh because the x is squared using the formula (x-h)^2 it shows a vertical graph but if the y^2 we use (y-k)^2 which opens horizontally.

  • @soysauce_4533
    @soysauce_4533 5 ปีที่แล้ว +27

    Thank you for sharing this, I have a math final tomorrow and I needed help on finding the directix with a given vertex and equation.

    • @davidkhoury205
      @davidkhoury205 16 วันที่ผ่านมา

      I hope you did well on your final 5 years ago. I have a pre calc final tomorrow lol. Trying to maintain my A.

  • @brianmclogan
    @brianmclogan  11 ปีที่แล้ว +6

    that is very possible, I have videos teaching it a couple different ways as well. Hope this way makes sense

  • @Jqmkhs
    @Jqmkhs 7 ปีที่แล้ว +7

    Thanks for the amazing video. You've cleared so much confusion I had over these, especially since the Common Core textbook just gives me a chart without showing me how to do problems like these step-by-step. You are an extraordinary teacher, and please keep posting more videos!

    • @brianmclogan
      @brianmclogan  7 ปีที่แล้ว +1

      really appreciate that Justin, I have no plans of stopping

  • @tanners3300
    @tanners3300 5 ปีที่แล้ว +1

    Your students are very lucky to have a prof. like you. Cuz Everytime I don't understand the lesson, I'll directly search for your videos.

  • @sanstheskeleton5573
    @sanstheskeleton5573 4 ปีที่แล้ว +15

    bruh i wish you were my precal teacher during quarantine

  • @welbymoore
    @welbymoore 4 ปีที่แล้ว +2

    I have my Calc II final tomorrow. These videos have really helped me!! 🙌

  • @jamesrichard6372
    @jamesrichard6372 5 ปีที่แล้ว

    Pushing me to reach my potential led me to dream big and do extraordinary things. Thank you my teacher!🙏🙏🙏🙏🙏🙏🙏🙏🙏

  • @lauraabromavage
    @lauraabromavage 5 ปีที่แล้ว +1

    Thank You!!! You have no idea how much I appreciate this video.

  • @FrenEditz
    @FrenEditz ปีที่แล้ว

    Mr. McLogan you are a lifesaver!

  • @DatMan0nTheMoon
    @DatMan0nTheMoon 7 ปีที่แล้ว +11

    THANK YOU SO MUCH YOU EXPLAINED IT BETTER THAN MY PROFESSOR!!!

    • @brianmclogan
      @brianmclogan  7 ปีที่แล้ว

      you are very welcome! happy to help

  • @biradjanrubenm.985
    @biradjanrubenm.985 9 หลายเดือนก่อน

    Man this video of yours is the best! Easy to understand Thank you for this!

  • @Grottogoob
    @Grottogoob 3 ปีที่แล้ว +1

    Holy crap, you are astounding! Thank you!

  • @00igloo
    @00igloo 11 ปีที่แล้ว +1

    You're the man, thank you for putting it so simply.

  • @thecornseller
    @thecornseller 2 ปีที่แล้ว +1

    this was very helpful, i was struggling to figure out what directrix and focus was so this helped a lot

  • @itzultrasonic634
    @itzultrasonic634 2 ปีที่แล้ว

    Thank you so much sir
    Love from India 🇮🇳🇮🇳

  • @realhuman4396
    @realhuman4396 ปีที่แล้ว

    Thanks, i missed a class of trigonometry, this helped me

  • @milocbc
    @milocbc 5 ปีที่แล้ว +2

    Thank you so much, you got straight to the point without confusing us. Now I won’t fail math

  • @ak_pmrjs
    @ak_pmrjs 3 ปีที่แล้ว

    These helps me a lot !! I finally able to graph my parabola and learn all the things when in fact what i am ask to find is only the vertex, focal distance,and the opening. 💖

  • @Camronrichard1
    @Camronrichard1 8 หลายเดือนก่อน

    This concept is super easy when everyone instructs it in the normal format, my quiz has it in a format that the lesson plan does not even explain it in.

  • @Augustus_Yechezqel
    @Augustus_Yechezqel 4 หลายเดือนก่อน

    you really helped a lot sir, thanks!

  • @stjarna5072
    @stjarna5072 3 ปีที่แล้ว

    Thank you soooo much😭😭😭 this video helped me a lot

  • @SZ-rz8hj
    @SZ-rz8hj 6 ปีที่แล้ว

    THANK YOU SO MUCH FOR THIS!!! I know I comment a lot on your videos.. but I cant express my thanks enough! THANK YOU!

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว

      you are very welcome Salem! happy to be able to help!

  • @mccauleybacalla2228
    @mccauleybacalla2228 2 ปีที่แล้ว

    thank you so much, this wasnt taught by my pre cal teacher shs stem

  • @businessaccount3177
    @businessaccount3177 ปีที่แล้ว

    bro is smart asf he might not make much as a teacher but im sure he makes a lot off these videos W hustle

  • @esharana3818
    @esharana3818 6 ปีที่แล้ว

    You are a better teacher than mine. I never understood this but now i do. Im so happy!! Thank you ❤️

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว +1

      awesome! happy to be able to help you out Esha

  • @kenny19142
    @kenny19142 7 ปีที่แล้ว +1

    Perfecttt, way better than my professor. Very clear and thorough! Good job. You get a cookie

  • @KumarNayan-cd6qd
    @KumarNayan-cd6qd 4 ปีที่แล้ว

    Love from india sir🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏❤️❤️❤️❤️❤️❤️

  • @zainodat2168
    @zainodat2168 6 ปีที่แล้ว

    This guy is literally the reason why I've passed geometry and Algebra II.

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว

      cheers to you Zain, keep working hard and happy to be there for . you

  • @theshoosher2566
    @theshoosher2566 6 ปีที่แล้ว

    This was a huge lifesaver. Thanks!

  • @beyoncebocado1688
    @beyoncebocado1688 3 ปีที่แล้ว

    Thank you so much, Sir, for sharing your knowledge to us.

  • @momalzahid4577
    @momalzahid4577 6 ปีที่แล้ว

    You explain really well. Thumbs up.

  • @Paul-kd3ui
    @Paul-kd3ui ปีที่แล้ว

    Would this be different for photons vs sound waves?

  • @cindywei863
    @cindywei863 6 ปีที่แล้ว

    Wow you are so good at explaining

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว

      just happy to be able to help

  • @jonelysais
    @jonelysais 5 ปีที่แล้ว

    big help in our society

  • @XxS1l3nTxa1Mx
    @XxS1l3nTxa1Mx 7 ปีที่แล้ว +1

    Wow great video

  • @ericmao1626
    @ericmao1626 ปีที่แล้ว

    I love how he is continuously giving weird looks to the students while teaching the lesson and always making sure they are still paying attention 🤣

  • @alessandroganino8626
    @alessandroganino8626 5 ปีที่แล้ว

    Thanks so much this is great!

  • @cosmickitty9533
    @cosmickitty9533 6 ปีที่แล้ว +2

    amazing lesson thank you! I can tell you really love to teach

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว +2

      happy to help, yes still enjoy my day job

  • @vijayfartyal6665
    @vijayfartyal6665 7 ปีที่แล้ว

    thanks sir too much helpful .
    from India

  • @pallavkumar7559
    @pallavkumar7559 6 ปีที่แล้ว +2

    Thanks a lot sir. Btw how to find length of latus rectum?

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว

      4p If I remember correctly!

  • @rencycelades8956
    @rencycelades8956 4 ปีที่แล้ว

    is it the same if the equation is opposite like side ward equation

  • @adamhogsed
    @adamhogsed 5 ปีที่แล้ว

    You’re a blessing

  • @NGarreau12
    @NGarreau12 11 ปีที่แล้ว +4

    thanks! we learned it differently, though... I think...

  • @dogselfie9838
    @dogselfie9838 6 ปีที่แล้ว

    thank you so much for this.. all I have to do is look at the board because everything is right there. thank you for doing that.😊😊😊

  • @astley2340
    @astley2340 7 ปีที่แล้ว

    Wow! This is so simple I never knew that! Thank you so so much!

  • @rayyan3253
    @rayyan3253 3 ปีที่แล้ว

    At 0:45, can someone please tell me how is the center ( -3,1 )

  • @zmalikmalik2454
    @zmalikmalik2454 12 ปีที่แล้ว

    This was really helpful thank you

  • @yoknight9197
    @yoknight9197 4 ปีที่แล้ว

    still watching ur videos in 2020

  • @davidela
    @davidela ปีที่แล้ว

    hello sir...how do i know its vertical or horizontal focus?

    • @brianmclogan
      @brianmclogan  ปีที่แล้ว +1

      if the x is squared it is vertical like a quadratic, if y then horizontal

  • @graysongallagher1660
    @graysongallagher1660 4 ปีที่แล้ว

    Bro you don't even realize how much you save high school math students

  • @adamdeshields8621
    @adamdeshields8621 7 ปีที่แล้ว +4

    Short and sweet.

  • @hanszoe5843
    @hanszoe5843 ปีที่แล้ว

    I don't know if you will respond to this but I'll still try my shot
    How do we find P if only the center/vertex is given and the parabola opens to the left?

    • @brianmclogan
      @brianmclogan  ปีที่แล้ว +1

      That is not enough information. You will need one more point unless it is assumed no dilation/stretch then p is 1/4

  • @shantaramzalte8565
    @shantaramzalte8565 4 ปีที่แล้ว

    धन्यवाद गुरुजी!

  • @dorenenguyen6210
    @dorenenguyen6210 11 ปีที่แล้ว

    I've been trying your method of adding P to h or K to find the focus, and it it just not working for any of the problems I'm doing. I tried it on the problem, 1/2x^2+6x-y+16=0. Could you help me out? Thanks!

  • @Jade_Le
    @Jade_Le 7 ปีที่แล้ว

    I don't know if you'll respond, but I have an upcoming test. I was able to easily follow what you were doing, but I didn't understand how you knew the equation had a vertical transverse axis.

    • @brianmclogan
      @brianmclogan  7 ปีที่แล้ว +1

      since x was squared I know the graph either opens up or down, if y was squared it would be horizontal

    • @pershop4950
      @pershop4950 7 ปีที่แล้ว

      When you have the form as y = x^2, then it is a vertical parabola. When you have the form x = y^2, then it is a horizontal parabola. Opening up, will be x^2. Opening down, will be -x^2. And opening right will be y^2, and similarly for opening left, which is -y^2.

  • @MrWilddingo
    @MrWilddingo 11 ปีที่แล้ว +2

    thank you so much!

    • @brianmclogan
      @brianmclogan  11 ปีที่แล้ว

      you are very welcome! happy to help

  • @jakesabandal9894
    @jakesabandal9894 4 ปีที่แล้ว

    I have a question!why is h,k is -3,1 not 3,-1?

  • @rBJ817
    @rBJ817 7 ปีที่แล้ว +2

    Thanks Brian

  • @mhikyjayno6063
    @mhikyjayno6063 3 ปีที่แล้ว

    How did you know sir that the focus
    (h, K+p), between K and p is add?

  • @tarnaka504
    @tarnaka504 5 ปีที่แล้ว +1

    thanks,🤩

  • @asiabibi1100
    @asiabibi1100 2 ปีที่แล้ว +1

    Can u explain 1 doubt of mine

    • @Ur.Stargirl
      @Ur.Stargirl 2 ปีที่แล้ว

      Your 10 years late hahaha

  • @monikayadav810
    @monikayadav810 7 ปีที่แล้ว +2

    thanks sir ji nice vedio

  • @gerrysins9600
    @gerrysins9600 5 ปีที่แล้ว

    i wish you're my real life teacher

  • @SlaYer-um7wb
    @SlaYer-um7wb 5 ปีที่แล้ว

    How do you know if a parabola is vertical or horizontal?

  • @johnmathewmanuel1933
    @johnmathewmanuel1933 3 ปีที่แล้ว

    is it not a negative 4p instead of positive? because it opens downward

  • @extremelyzavier2302
    @extremelyzavier2302 2 ปีที่แล้ว

    This guys the Johnny Sins of math

  • @ravikantsahani7390
    @ravikantsahani7390 7 ปีที่แล้ว

    thank you sir ,i confused in this type question but I am clear

    • @brianmclogan
      @brianmclogan  7 ปีที่แล้ว +1

      confused or clear?

    • @cheezgaming6397
      @cheezgaming6397 4 ปีที่แล้ว

      @@brianmclogan He is saying that he was confused, but you cleared it for him

  • @florisalove1
    @florisalove1 6 ปีที่แล้ว

    Hi, how do you know if a parabola opens vertically or horizontally?

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว +3

      from an equation? x^2 then vertically, y^2 then horizontally

  • @elilatiolais
    @elilatiolais 3 ปีที่แล้ว

    Literally saving me in finals

  • @jrymy8003
    @jrymy8003 ปีที่แล้ว

    hi sir may i ask why it turned out to be 3/2 I don't get it po , im slow in math 1- (-1/2)

  • @wilsonlechuza471
    @wilsonlechuza471 7 ปีที่แล้ว

    what is the form of the parabula is it upward or downward?

  • @vijayfartyal6665
    @vijayfartyal6665 7 ปีที่แล้ว

    sir, if the parabola in form of
    (y-h)^2=4p(x-k)
    will directix be x=h-p

  • @wipcreme
    @wipcreme 4 ปีที่แล้ว

    How do you know its vertical or horizontal by just looking at the equation?

    • @melakredwan
      @melakredwan 3 ปีที่แล้ว +1

      the equation has x^2 so its vertical but if it was y^2 then is horizontal.

  • @rjf5790
    @rjf5790 6 ปีที่แล้ว

    Why you add the p on the k?, since it's horizontal shouldn't it be on the h?

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว +1

      no x is squared so it is a vertical parabola (quadratic equations)

  • @weknee9194
    @weknee9194 ปีที่แล้ว

    Im a bit confused instead of (x-h)²=4p(y-k) why not(x-h)²=-4p(y-k)??

  • @sethwilliams3683
    @sethwilliams3683 7 ปีที่แล้ว

    Thank you, this was helpful. My math book sucks...

    • @brianmclogan
      @brianmclogan  7 ปีที่แล้ว

      sorry to hear, happy to help

  • @jackeddy7
    @jackeddy7 2 ปีที่แล้ว

    I go to Mandarin high school and I’m pre cal as a sophmore I wish I had you I know you used to teach here so I’m sad I missed out I do not like my current teacher in terms of teach ability

  • @janethllolong4749
    @janethllolong4749 7 ปีที่แล้ว

    Thank you so Muchhh

  • @crytlnn6503
    @crytlnn6503 5 ปีที่แล้ว +3

    How is 1 - (-1/2) = 3/2

    • @lilygreenhaven5646
      @lilygreenhaven5646 8 หลายเดือนก่อน +1

      Minus a negative is adding a positive

  • @princerajan3235
    @princerajan3235 3 ปีที่แล้ว

    Do parabola even have a centre

  • @chapmanschivera7846
    @chapmanschivera7846 2 ปีที่แล้ว

    homie savin me on my calc exam tmr. 9 years later... lmao

  • @brianmclogan
    @brianmclogan  11 ปีที่แล้ว

    that is really sad, sorry you have to go through an experience like that.Schools are bound to change

  • @maccole69
    @maccole69 11 ปีที่แล้ว

    I am confused at 1:40. how is -2=4p?

    • @maccole69
      @maccole69 11 ปีที่แล้ว

      I get it now

    • @brianmclogan
      @brianmclogan  11 ปีที่แล้ว

      okay! let me know if there are any other parts

  • @luisiveseo2068
    @luisiveseo2068 3 ปีที่แล้ว

    How about y²=16x

  • @flameforce4000
    @flameforce4000 11 ปีที่แล้ว

    Why can't our math teacher teach like you..., all she does is give us papers and starts solving problems like there's no tomorrow, some teachers seriously need to be replaced!

  • @somerandomguy7458
    @somerandomguy7458 4 ปีที่แล้ว

    why is it -3,1 ?

  • @calculotv1
    @calculotv1 6 ปีที่แล้ว

    Excelente!!

  • @kimyates6561
    @kimyates6561 7 ปีที่แล้ว

    thx so much

  • @jaredchavez7983
    @jaredchavez7983 5 ปีที่แล้ว

    gracias papa

  • @ainoba16
    @ainoba16 7 หลายเดือนก่อน

    I think the formula for focus and directrix are not accurate. When the p becomes negative, the formula for focus is (h), (k-p) while for directrix is y= (k+p)

  • @kroidtek
    @kroidtek 2 ปีที่แล้ว

    1:17 🅿ushin 🅿

  • @onemorearnav
    @onemorearnav 6 ปีที่แล้ว

    Again I am telling you. You are a good teacher!!!! But u get so confused while solving it and miss important things 😒

    • @brianmclogan
      @brianmclogan  6 ปีที่แล้ว

      sometimes I confuse myself, yes

    • @daniellaa4715
      @daniellaa4715 6 ปีที่แล้ว

      Brian McLogan who cares no one is perfect! You make everything easy to understand. You’re doing amazing thank you SO much!!!😊

  • @temesgen24
    @temesgen24 ปีที่แล้ว

    I’m not sure why you adding 4p because there is no 4 you’re just making it up.

  • @sanas6065
    @sanas6065 4 ปีที่แล้ว

    Can someone tell me why he put 4p???

  • @ravikantsahani7390
    @ravikantsahani7390 7 ปีที่แล้ว

    clear