Math Olympiad Question with

Поділитися
Вставка
  • Опубліковано 1 гру 2021
  • Denis from ‪@ThePhysicsMathsWizard‬ challenges me with a question from the Vietnam Math Olympiad about the floor function... #tomrocksmaths #thephysicsmathswizard
    The question asks for all positive solutions to the equation 0.9t = floor(t) / (t - floor(t)). My approach was to first rule out integer solutions and then solve for t in the range (n, n+1). This leads to a quadratic equation and a series of inequalities that need to be satisfied for the solutions to be valid.
    Check out Denis's channel ‪@ThePhysicsMathsWizard‬ here: / thephysicsmathswizard
    Produced by Dr Tom Crawford at the University of Oxford. Tom is an Early-Career Teaching and Outreach Fellow at St Edmund Hall: www.seh.ox.ac.uk/people/tom-c...
    For more maths content check out Tom's website tomrocksmaths.com/
    You can also follow Tom on Facebook, Twitter and Instagram @tomrocksmaths. / tomrocksmaths
    / tomrocksmaths
    / tomrocksmaths
    Get your Tom Rocks Maths merchandise here:
    beautifulequations.net/collec...

КОМЕНТАРІ • 81

  • @TomRocksMaths
    @TomRocksMaths  2 роки тому +18

    For more collabs with Tom check out the designated playlist here: ua-cam.com/play/PLMCRxGutHqflwDzFFt33UwO8ncqg4GEZj.html

  • @ThePhysicsMathsWizard
    @ThePhysicsMathsWizard 2 роки тому +209

    Great job Tom, am glad for working with you on this one, I like the way you solved the problem and the thought process. Cheers

    • @TomRocksMaths
      @TomRocksMaths  2 роки тому +22

      Thanks for joining Denis!!

    • @leif1075
      @leif1075 2 роки тому +3

      @@TomRocksMaths Thanks for sharing. I hope you can respond to my other comment when you can. Thanks very much.

    • @Triskelion345
      @Triskelion345 2 роки тому +3

      Thanks 😁

  • @boualemhabib9949
    @boualemhabib9949 2 роки тому +18

    Humility is so intrinsic to your nature that I truly believe that many people didn't think that you already knew the solution to the equation as soon as it was within your eyesight. I have followed you on youtube for a while. I enjoyed your 125 miles self inflicted torture run. As the french would say, de la folie pure.Tout mon respect.
    you are a true teacher. Chapeau.

  • @susie7301
    @susie7301 2 роки тому +27

    Wow, I wasn't expecting to find a maths video so interesting! It'd be really cool if you could do some videos on similar questions, and how you can practise to improve your problem solving skills! I'm an alevel (further) maths student and although I find the class content fine, I struggle with things like the senior maths challenge as I just can't think straight to a solution haha

  • @eggtimer2
    @eggtimer2 2 роки тому +1

    Very well done. It is inspiring!

  • @shivashankar28
    @shivashankar28 2 роки тому +34

    Amazing prof, haven't learnt this as an undergraduate in Electrical Engineering, but pretty cool !

    • @husseinmohamud6506
      @husseinmohamud6506 2 роки тому +1

      How hard is eee at university?

    • @m.moonsie
      @m.moonsie Місяць тому

      @@husseinmohamud6506 very. black magic

  • @maxime863
    @maxime863 2 роки тому +3

    Great video Dr. Tom

  • @prismblack5003
    @prismblack5003 2 роки тому +1

    You guys are Brilliant 👌🏾

  • @abbe23456789
    @abbe23456789 2 роки тому +1

    Great video! Make more videos like this, were you try to solve problems live. It's really interesting.

  • @domc3743
    @domc3743 2 роки тому +18

    I love how everything follows logically (i.e no magic tricks) really great stuff Tom

  • @babagaming4943
    @babagaming4943 2 роки тому +1

    Woooo this collaboration was nice the number is so cool. I knew this channel from math physics wizard but their is also good content. Yap guys keep on keeping on

  • @phenixorbitall3917
    @phenixorbitall3917 2 роки тому +7

    Great :) It is a cool mixture of nerdyness and useful entertainment. Watching both of you doing maths feels like listening to two musicians embarking on some intense jazzy maths improvisation - pretty cool. It made me smile at the end :) Please continue collaborating together!

  • @Twister15X
    @Twister15X 2 роки тому +11

    I've done it in the same way hahaha, the only diference is that a called t = n + e, where n is an integer and 'e' is a numbem between 0 and 1. So in the end what changed was the condition that would filter the values of n.

  • @nuranichandra2177
    @nuranichandra2177 Рік тому +1

    Admire the fantastic problem and solution strategy

  • @RobertSmith0008
    @RobertSmith0008 2 роки тому

    Moreover, to see why the first t doesnt work, it is easy to see from the expression (with negative radical) that t < n/2, which contradicts the fact that t >n

  • @floreaciprian9742
    @floreaciprian9742 2 роки тому +1

    These videos are so much fun to watch. We get to meet other youtubers passionate about maths, we see both sides challanged, we see the thought process both. This idea to involve other people was just brilliant. Thanks and i hope we get to see more

  • @eugeneyong6674
    @eugeneyong6674 2 роки тому +1

    Amazing!

  • @CommanderdMtllca
    @CommanderdMtllca 2 роки тому +2

    Do more like this!!! I love seeing math videos where someone has to think out loud instead of guiding the video with a scripted solution.

  • @antooshon4904
    @antooshon4904 2 роки тому +1

    awesome man

  • @desertstorm6927
    @desertstorm6927 2 роки тому

    I like how doctor aproaches every problem.
    Also i like how innocent this guy looks. wow 🥰

  • @tanpham762
    @tanpham762 9 місяців тому

    Maths is always interesting!

  • @strafehelix
    @strafehelix 2 роки тому

    It'll be interesting to see you do a engineering exam, it's based upon maths, mechanical which is beams and All and electrical

  • @parkie8167
    @parkie8167 2 роки тому +1

    God this was such a fun problem. Gonna go look at the vietnamese math olympiad lmao

  • @asd-bl5ur
    @asd-bl5ur 2 роки тому

    An alternate solution could be forming a quadratic in fractional part of t, and then using the concept of location of roots to figure out the answer

  • @iteerrex8166
    @iteerrex8166 2 роки тому +1

    Seemingly simple but a tricky little problem. Nicely done professor.

  • @rehab3398
    @rehab3398 2 роки тому +7

    Never seen a mathematician with the drip that this man has

  • @nDreaw12
    @nDreaw12 2 роки тому +5

    Damn I feel so dumb by this Video but still love it and appreciate all ur Vids Tom 👌

  • @RC32Smiths01
    @RC32Smiths01 2 роки тому +5

    Amazing as always, Tom!

  • @rijulbarot2195
    @rijulbarot2195 2 роки тому +19

    Hey, I found a method free of the quadratic complications, so I thought id share it. Write the greatest integer t to be x, and then t - x = f, ( f for fraction :D and it goes from (0,1)) , so the equation becomes 0.9(x+f) = x/f, which implies 0.9(x+f) > x , so x < 9f and from the range of f we get the possible values of x to be 1,2,3,4,5,6,7,8. Cheers and great video btw!

    • @DmitDmit1
      @DmitDmit1 2 роки тому +1

      I've solved it the same way. But I find his solution is more straightforward. And you still have to express f in terms of x, can't avoid dealing with quadratic here.

    • @TomRocksMaths
      @TomRocksMaths  2 роки тому

      nice!

    • @sumitprabhakar177
      @sumitprabhakar177 2 роки тому

      After you get 0.9t = floor(t)/integer part (t) then it can be easily analyzed graphically

  • @NateCrownwell
    @NateCrownwell 2 роки тому +1

    Really cool math problem :)

  • @ashugoshu
    @ashugoshu 2 роки тому

    I was that kid who always sleep when hearing about equations but I'm finding it more interesting RN . Well I've been watching Tom's content for over a year I like his contents and he is cute as always 😙

    • @TomRocksMaths
      @TomRocksMaths  2 роки тому +1

      amazing, keep at it and you'll be a maths fan in no time!

  • @RobertSmith0008
    @RobertSmith0008 2 роки тому

    you can show immediately that n is less than 9 as follows,:
    From the equation you get that t - n = n / (0.9 t) which should be less than 1, This implies that 10n < 9t. But t

  • @aashsyed1277
    @aashsyed1277 2 роки тому +2

    I watch that channel!!!!

  • @zarifahmed8549
    @zarifahmed8549 2 роки тому +1

    You should make a video to advice students about A levels and GCSEs

    • @TomRocksMaths
      @TomRocksMaths  2 роки тому +1

      I discuss this a lot in my 50k Q&A video here: ua-cam.com/video/2OvlZxteE2w/v-deo.html

  • @xamael1989
    @xamael1989 2 роки тому

    Lovely

  • @GreenMeansGOF
    @GreenMeansGOF 2 роки тому +1

    I think it’s important to note that up until the smiley face, n could have been 0. I don’t think you noticed that that case got eliminated.

  • @JanxakaJX
    @JanxakaJX 2 роки тому

    You made this really fun Tom. Thanks for making maths fun :) Also, really impressed by how well you did this question and your reasoning

  • @chad_the_stud
    @chad_the_stud 2 роки тому +1

    analytical thinking, problem solving skills are valid if you know the details of the topic

  • @robinrahman8623
    @robinrahman8623 2 роки тому +1

    I hope everyone else's face lit up the way mine did when you were close to finding the solution .o.

  • @natural-926
    @natural-926 2 роки тому +3

    Tom, you are the best and coolest Math Professor in the World

  • @dave_thebrave
    @dave_thebrave Рік тому

    at 13:15 aw math is gonna be very interesting to see how much work this guy

  • @gametimewitharyan6665
    @gametimewitharyan6665 5 місяців тому

    I am so happy to solve this question myself, even though I don't prepare for Olympiads and I am sooo much happy because I am only in class 10th 🥳🥳🥳

  • @ekisvioleolivaradamos6701
    @ekisvioleolivaradamos6701 2 роки тому +1

    amazing....

  • @eliascabrera5539
    @eliascabrera5539 2 роки тому +1

    Thats Ninja

  • @helloitsme7553
    @helloitsme7553 2 роки тому

    I first thought it said 0 times 9 and I was like what is this a prank

  • @naveenwanigasundara2206
    @naveenwanigasundara2206 2 роки тому +2

    cool pro

  • @kojoabiam7688
    @kojoabiam7688 2 роки тому

    Awesome!👍🎄 I follow you from Ghana. Please adjust your light, there seems to be a glare on the board. Thanks

  • @vansf3433
    @vansf3433 Рік тому

    Why do you guys like High school or SE maths?

  • @gordonmacgregor7668
    @gordonmacgregor7668 2 роки тому +1

    me sitting pretending like I have any clue wtf is going on

  • @Kimm4321
    @Kimm4321 2 роки тому +2

    I'm sorry Tom my girfrend unliked this video but dont worry I undisliked and liked your video. Keep it up super awesome!

  • @sztojanbarna
    @sztojanbarna 2 роки тому

    I understand math until it doesn't contain letters!

  • @weonlygoupfromhere7369
    @weonlygoupfromhere7369 2 роки тому

    Man has a massive noggin. I don't even know where to start

  • @2sdd
    @2sdd 2 роки тому

    dude seems like a good teacher but i cant focus cuz he looks like a clown

    • @boualemhabib9949
      @boualemhabib9949 2 роки тому +3

      it takes a clown to spot another., however, you sir, are the exception to the rule. Enough said ///.