The Cosine Rule - GCSE Higher Maths

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  • Опубліковано 22 гру 2024

КОМЕНТАРІ • 79

  • @thatoneguy.3548
    @thatoneguy.3548 4 місяці тому +9

    I cannot thank you enough. Listening to this in class helped me so much with learning such a hard concept in year 11

  • @WaliullahAhmed-cz7nz
    @WaliullahAhmed-cz7nz 3 місяці тому +24

    i cant thank you enough i have moved from foundation to higher and im going yr11 i was having such a hard time understanding this and you just taught me in a matter of minutes

    • @1stClassMaths
      @1stClassMaths  3 місяці тому +5

      Glad to be of service!

    • @fast9952
      @fast9952 Місяць тому

      @@1stClassMathsi'm in 9th grade gotta do this already and the trimester is barely mid term.... I can't imagine 11th grade

    • @cocolata9744
      @cocolata9744 Місяць тому +1

      ​@@fast9952 you better start imagining it y11 is stressful 😭

    • @deadm4n881
      @deadm4n881 21 день тому

      hi what did you get in ur mocks if your comfortable telling as i've moved from foundation aswell

    • @pxlarbexr
      @pxlarbexr 18 днів тому

      @@fast9952year 9??

  • @ALARIO-uf6wp
    @ALARIO-uf6wp 6 місяців тому +18

    thanks for making me understand this in then minutes, you are incredible

  • @x7.fa_
    @x7.fa_ День тому

    just wanted to leave a huge thank you, I've been crying all day thinking i will never understand the exam material until i found this video

    • @1stClassMaths
      @1stClassMaths  День тому

      No problem at all. I appreciate maths is not always the easiest subject but with time and practice you can get there. Good luck for your exam.

  • @mxiisty_alxynxx
    @mxiisty_alxynxx 8 місяців тому +48

    Yessss tyyy I have an exam tomorrow and I had no clue until I found this 😊😊🎉

    • @ammarahissufo6482
      @ammarahissufo6482 8 місяців тому +3

      good luck in ur exam

    • @mryamsradio
      @mryamsradio 7 місяців тому +6

      mines in an hour 😭😭 watching this to learn how to do this

    • @ejxnsticks9889
      @ejxnsticks9889 6 місяців тому +1

      same lmao

    • @starktony1354
      @starktony1354 4 місяці тому +2

      One hour is crazy did you pass?

    • @oyunasg9657
      @oyunasg9657 3 місяці тому +1

      How did your exam go

  • @diggisirajo
    @diggisirajo 6 місяців тому +9

    This channel is underated

    • @1stClassMaths
      @1stClassMaths  6 місяців тому +5

      Thanks! This comment is underrated.

  • @ZoroZoro-yw2bz
    @ZoroZoro-yw2bz 2 місяці тому +2

    tysm this channel is so underrated

  • @ReemAsif
    @ReemAsif 3 місяці тому +1

    Thank you so much. You are indeed the best person on this earth and u deserve the whole worlds love

    • @1stClassMaths
      @1stClassMaths  3 місяці тому +1

      Thanks. Might be some slighly better people though!!

  • @ramratan8426
    @ramratan8426 9 місяців тому +1

    Thanks for making me understand a formula which was difficult for me to understand :)

  • @neco6696
    @neco6696 6 місяців тому +4

    this deserves more likes

  • @michaelsuja4256
    @michaelsuja4256 4 місяці тому +5

    thanks i will pass my exams

  • @kinzabibi7716
    @kinzabibi7716 Місяць тому +1

    thank you , this video is really helpful!!

  • @MuneebMakes
    @MuneebMakes 3 місяці тому +1

    When I type both of the fractions at 5:44 and 7:00 into my calculator, it gives me totally different answers than to what's shown. Please could you offer some help as to why that could be because I am really stuck on that for the time being

    • @1stClassMaths
      @1stClassMaths  3 місяці тому

      Hey. You probably have the wrong angles mode set. Check if your calculator is in degrees mode.

    • @MuneebMakes
      @MuneebMakes 3 місяці тому

      ah yeah thanks man my bad @@1stClassMaths

  • @Kandeling
    @Kandeling 3 місяці тому +1

    Thank you for explaining however I have one problem, when I type the exact same formula on the calculator, I get a whole different result and it's the same thing with all the other exercises I've done...

    • @1stClassMaths
      @1stClassMaths  3 місяці тому

      Hi your calculator is most likely set to the wrong angle unit eg radians.

    • @Kandeling
      @Kandeling 3 місяці тому

      @@1stClassMaths Yes thank you, I just figured it out

    • @1stClassMaths
      @1stClassMaths  3 місяці тому +1

      Always test sin 30 as you want it to be 0.5 😄

  • @anaselkelani3478
    @anaselkelani3478 2 місяці тому

    Can you please post a video on quadratic expressions i have a exam after tomorrow plz help

  • @moonknight6411
    @moonknight6411 7 місяців тому +1

    W for explaining it so well thank you so much❤❤

  • @savageanimator
    @savageanimator 12 днів тому

    But when changing the formula to find the missing angle, why don't we shift COS(A) directly to the other side?

    • @1stClassMaths
      @1stClassMaths  12 днів тому

      Without the 2bc you mean?
      If so you cannot do that because it is all one term -2bcCos(A).

    • @savageanimator
      @savageanimator 12 днів тому

      @@1stClassMaths But those are multiplying, so can't they be separated, like you did in the next step when 2bcCos(C) was left alone so we moved Cos(C) to the other side?

    • @1stClassMaths
      @1stClassMaths  12 днів тому +1

      You probably want to not think about things "shifting" or "moving" as this causes confusion. When rearranging we must do the same thing to both sides. If you were to try to remove the CosA from the right hand side at the start you must divide both sides by CosA. This would lead to
      a^2 / cosA = b^2 / cos A + c^2 / cos A - 2bc
      As you can see we no longer have cosA with the 2bc but we now have cosA in many other places that we do not want it.
      What we need to do is isolate the term with the cosA in it, which is -2bcCosA. We do this by adding 2bcCosA to both sides (and also subtracting a^2 from both sides).

    • @savageanimator
      @savageanimator 9 днів тому

      @@1stClassMaths Thanks a lot! 😀😀👍👍

  • @MetehanErgene-o6f
    @MetehanErgene-o6f 2 місяці тому +1

    Thank you my brother my igc is soon and i forgot this formula

  • @kothongohingoongoon7224
    @kothongohingoongoon7224 22 дні тому

    How did you cancel a² from both sides when there was only one?

    • @1stClassMaths
      @1stClassMaths  22 дні тому

      It only cancels from one side. The other side introduces - a^2

  • @TheOnlyZackshadyK98
    @TheOnlyZackshadyK98 Місяць тому

    thank you very very much, it helped more than enough:))

  • @RinoVagnoni
    @RinoVagnoni 4 місяці тому +1

    Grazie prof.❤

  • @danmike2305
    @danmike2305 2 місяці тому

    When to use cosine rule as opposed to sine rule ?

    • @1stClassMaths
      @1stClassMaths  2 місяці тому +1

      Explains at the end of the video.

    • @Akin-v5d
      @Akin-v5d 2 місяці тому

      @@1stClassMaths is this for gcse math or gcse further math?

  • @ast3r0id
    @ast3r0id 8 місяців тому

    does it matter if we put our answer in a different decimal place like 2 dp if they don't specify?

    • @1stClassMaths
      @1stClassMaths  8 місяців тому +1

      Nope you will be ok. I’d go 1 or 2 dp for most if it doesn’t say.

    • @siddhantdev4036
      @siddhantdev4036 7 місяців тому

      usually the degree of accuracy is mentioned on the front of the paper. its safest to follow that one!

  • @madblox252
    @madblox252 5 місяців тому

    so USEFULL!!!!

  • @muhammedkadu6592
    @muhammedkadu6592 4 місяці тому

    Thanks man i got exam in a month

  • @khadijaalansi7591
    @khadijaalansi7591 3 місяці тому

    Thank you 👍🏻

  • @JacksonMaraba-r6u
    @JacksonMaraba-r6u Місяць тому

    Thanks ❤️

  • @AmeeraRolle-Marshall
    @AmeeraRolle-Marshall 9 місяців тому +1

    Would this ever come up in a non calculator?

    • @1stClassMaths
      @1stClassMaths  9 місяців тому +4

      Yes. Quite possibly using an exact trig value like cos30, cos45, cos60 or even cos120.

  • @errresh473
    @errresh473 Місяць тому

    Your a legend

  • @Goku_Black4444
    @Goku_Black4444 6 місяців тому +2

    FINAL MATHS EXAMMM🎉🎉🎉🎉🎉🎉

  • @yunaa____
    @yunaa____ 8 місяців тому

    hey my teacher taught us cosine rule as
    a²= √b²+c²-2abcos a 1:06

    • @1stClassMaths
      @1stClassMaths  8 місяців тому +2

      What would be a = rather than a^2 =

  • @khadijaalansi7591
    @khadijaalansi7591 3 місяці тому

    I like it too much😍

  • @damayanthiperera3327
    @damayanthiperera3327 Місяць тому

    1st class math = many maths teachers at school and 1.30 hours in 10 minutes

  • @m7mdfahd-wn6cf
    @m7mdfahd-wn6cf 6 місяців тому

    LIFE SAVOR THANBK YOU

  • @tastyfood2020
    @tastyfood2020 7 місяців тому

    I wonder why is this formula is similar as this formula
    (b-c)^2 i think there might be some relationship
    There's just add cos(A) with -2bc
    This is suspicious

    • @JacobMelia0046
      @JacobMelia0046 6 місяців тому

      everything in maths is related coming from a university student, its all connected in subtle ways

  • @Biggleton1
    @Biggleton1 6 місяців тому

    paper 3 predicted paper should be the best one!!!

  • @Den-TS
    @Den-TS 18 днів тому

    love u

  • @jawadbaloch7588
    @jawadbaloch7588 Рік тому +2

    ❤❤jawad. T

  • @stutilly2332
    @stutilly2332 2 місяці тому

    Hi .Answer I'm getting at 7.31 is 69.62591067.I've checked that calculator is in degrees.I get the same answer using an online scientific calc. Please help

    • @1stClassMaths
      @1stClassMaths  2 місяці тому +1

      You are not typing in the negative sign.