Arithmetic mean vs Geometric mean | inequality among means | visual proof

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  • Опубликовано: 16 сен 2024
  • hi~
    It's quite hard to upload videos from china because of RUclips being banned, but I'll be back home in two/three months and will be uploading more frequently (i will try at least).
    Same thing with Patreon..
    _________________________________________________________________
    Support my animations on:
    / think_twice
    _________________________________________________________________
    Any further questions or ideas:
    Email - thinktwiceask@gmail.com
    Twitter - / thinktwice2580
    _________________________________________________________________
    Programs used:
    - Cinema 4D
    - Adobe Premiere Pro
    - Processing
    _________________________________________________________________
    Music:
    "so far away" by outlax

Комментарии • 135

  • @Mathologer
    @Mathologer 6 лет назад +282

    Very nice as usual. Your videos really deserve to be known more widely :)

    • @ThinkTwiceLtu
      @ThinkTwiceLtu  6 лет назад +17

      Mathologer thank you :)

    • @trobin
      @trobin 6 лет назад +1

      Mathologer speak of the devil

    • @user-ie2sv1ri8k
      @user-ie2sv1ri8k 6 лет назад

      Yeah,it is very easy for me to understand.

    • @kaustubha7371
      @kaustubha7371 6 лет назад +2

      Two of my most favourite channels in one comment section.

    • @brogcooper25
      @brogcooper25 5 лет назад

      You as well.

  • @iorek4149
    @iorek4149 6 лет назад +13

    This is one of the most under-viewed, under-rated videos I've found to date. Well done.

  • @aldolunabueno2634
    @aldolunabueno2634 6 лет назад +11

    I love your content, and I feel identified with it. Some time ago I discovered "Proofs without words", and was completely fascinated. See a figure for five minutes, and then, like a lightning bolt, realize how obvious it was. Most people will never use the mathematics that goes the most to add and multiply. If this were taught in schools, at least then they could tell how beautiful it is. I hope you keep growing, and that you have the support you deserve for this job.

  • @diligar
    @diligar 6 лет назад +4

    This is such a beautiful way to show that inequality! I’m absolutely blown away

  • @plominecraft8852
    @plominecraft8852 6 лет назад +4

    Awesome video man!
    Keep the hard work :D

  • @KnThSelf2ThSelfBTrue
    @KnThSelf2ThSelfBTrue 6 лет назад +1

    Here from 3b1b! Really solid visual explanations. Very intuitive.

  • @ashutoshmahapatra537
    @ashutoshmahapatra537 4 года назад +1

    Your videos are my definition of perfect.

  • @AlexandrBorschchev
    @AlexandrBorschchev 3 года назад

    this is the most creative and unique math channel ever hands down. just out of the world talent, you can't find any other channel that does this.

  • @nasim09021975
    @nasim09021975 5 лет назад +1

    What a superb geometrical proof! 🙂

  • @atomiccompiler9495
    @atomiccompiler9495 6 лет назад +2

    I love your videos, they are really the bestest best over the whole youtube, and nothing gives me goosebumps like when I see your notifications. Please don't ever stop ! ♥

  • @NarutoShippudenIntro
    @NarutoShippudenIntro 6 лет назад +11

    Ayy he's back lovely content

  • @vpambs1pt
    @vpambs1pt 6 лет назад +2

    Nice to know you're "back" ^.^

    • @ThinkTwiceLtu
      @ThinkTwiceLtu  6 лет назад +1

      nice to know you're still here haha

    • @vpambs1pt
      @vpambs1pt 6 лет назад

      What's the use of the geometric mean?
      nice video, as always, good intuiton and music!

  • @satyambhatia9427
    @satyambhatia9427 6 лет назад

    You're doing a great job. Keep it up. Your channel surely deserve more followers.

  • @brogcooper25
    @brogcooper25 5 лет назад +2

    Everything about this is wonderful.

  • @ThoughtsEtcEtcEtc
    @ThoughtsEtcEtcEtc 2 года назад

    Such a great video and visualization. ❤️🙏

  • @yamansanghavi
    @yamansanghavi 6 лет назад +3

    Perfect as always.

  • @hpp6116
    @hpp6116 6 лет назад

    Beautiful animation!

  • @Dr.Waffles
    @Dr.Waffles 6 лет назад

    That smooth animation woah

  • @aleksandersabak
    @aleksandersabak 4 года назад +1

    How about the unloved harmonic mean? 2/(1/a + 1/b)? I kow it's allways smaller or equal to the geometric mean, but is there a nice graphical proof like this?

  • @fawadmirza.
    @fawadmirza. 6 лет назад +1

    Awesome as always

  • @txikitofandango
    @txikitofandango 4 года назад +1

    Great animation! It's very clear that h must always be less than or equal to r, but how would you prove that rigorously?

  • @michalnemecek3575
    @michalnemecek3575 6 лет назад +1

    Nice visualization of the geometric mean. BTW how do you visualize the geometric mean of 3 numbers?

  • @JoaoVitor-go2ph
    @JoaoVitor-go2ph Год назад

    bro I love what you do

  • @pushkarshukla1229
    @pushkarshukla1229 3 года назад

    Beautiful video

  • @ShaileshDagar
    @ShaileshDagar 4 года назад

    Simply loved it!

  • @farhadghaseri2013
    @farhadghaseri2013 3 года назад

    incredibly great

  • @-Kerstin
    @-Kerstin 5 лет назад

    Awesome, thanks

  • @bwayagnesarchives
    @bwayagnesarchives 6 лет назад

    I love these content! Keep it up

  • @arifahmad-7261
    @arifahmad-7261 3 года назад +1

    Cool

  • @dragoncurveenthusiast
    @dragoncurveenthusiast 6 лет назад +3

    Math is so beautiful!

  • @Magnasium038
    @Magnasium038 6 лет назад

    This is a great visualization! I'm not sure if your style is to teach or guide, but I felt the ratios at similar triangles thing went too fast

  • @JorgetePanete
    @JorgetePanete 6 лет назад +1

    everything about this is perfect

  • @prakharshukla8086
    @prakharshukla8086 Месяц назад +1

    I don't understand why are we making this semicircle can somebody explain?

  • @Zaspar
    @Zaspar 6 лет назад +10

    How do you know the triangles are similar?

    • @2000maichel
      @2000maichel 6 лет назад +5

      the top angle is 90

    • @toferg.8264
      @toferg.8264 6 лет назад +9

      This confused me for a moment too.
      Yes the top corner (of the combined triangle) is 90 degrees. And triangles always sum up to 180 degrees.
      Therefore in the bottom right (your right) of the combined triangle, is some portion of the _remaining_ 90.
      Therefore the bottom left (your left) of the combined triangle, is the _other_ portion of the _remaining_ 90 degrees.
      One hint the video gave, was by aligning the two triangles the same.
      The smaller triangle has the _other_ portion of the _remaining_ 90 degrees of the combined triangle. The smaller triangle is also a right triangle. Therefore, its corner that makes up the combined triangle's right angle, is also the original portion of the _remaining_ 90 degrees.
      Therefore the triangles have the same corners.
      Therefore the proportions of their sides are the same.

    • @kaustubha7371
      @kaustubha7371 6 лет назад

      Same common Hypotenuse

    • @ultimatewierdness
      @ultimatewierdness 4 года назад

      I'm a bit late to the party, but a more thorough explanation would be to use what's known as the inscribed angle theorem. It states that the inward angle towards two points on the circle from another point on the circle is half of the outward angle if the third point was instead located in the middle if the circle. It's a bit hard to put into words, so look it up yourself. Since we're dealing with a half-circle, the second outward angle would be 180 degrees (forming a line across the diameter), thus the inward (inscribed) angle would be 90 degrees. This can then be combined with the combined angle of the triangle being 180 degrees to show that they are similar (see previous comment).

    • @AlexandrBorschchev
      @AlexandrBorschchev 3 года назад

      look up thale's theorem.

  • @V_V-V_V
    @V_V-V_V 6 лет назад +5

    This also shows that AM = GM only if a = b :)

    • @captainsnake8515
      @captainsnake8515 4 года назад

      Uhhh... what? It clearly does not only show that.

    • @bernd8608
      @bernd8608 4 года назад

      @@captainsnake8515
      He said it does, he doesn't said it ONLY does. Do you even English?

  • @satviksharma1146
    @satviksharma1146 6 лет назад

    Nailed it

  • @FatihKarakurt
    @FatihKarakurt 6 лет назад

    Visuals are great, I think music may need more attention!

  • @RG-pr5xx
    @RG-pr5xx 5 лет назад +2

    Wait.. can someone explain how the 2 triangles had all equal angles?

    • @Extraordinary10s
      @Extraordinary10s 5 лет назад

      Rajdeep Gadgil This is due to the fact that as the triangle is drawn in a semicircle, with its two ends at the end of the diameter, then it is a right angled triangle, that is, one of its angles is 90 degrees.

  • @stephenstark313
    @stephenstark313 3 года назад

    its damn beautiful...

  • @chiletv2936
    @chiletv2936 6 лет назад

    amazing

  • @brogcooper25
    @brogcooper25 4 года назад

    What is this genre of music called and what else is similar? It's not something I would normally listen to but I really like it.

  • @joesiu4972
    @joesiu4972 6 лет назад

    very nice my friend

  • @erikamayumi2134
    @erikamayumi2134 6 лет назад

    nice!

  • @bhavyajainnd
    @bhavyajainnd 6 лет назад

    What an amazing analogy. I know an arithmatic proof but this is way prettier

  • @NoNTr1v1aL
    @NoNTr1v1aL 6 лет назад +3

    That was awesome! The music is too. What is its name?

    • @ThinkTwiceLtu
      @ThinkTwiceLtu  6 лет назад +6

      thanks man. I honestly just found this song on my pc and I don't rly know the name... If anyone finds out let me know, i will include it in the description.

    • @Simmimmi99
      @Simmimmi99 6 лет назад +5

      "so far away" by outlax

  • @emreozkarasn9226
    @emreozkarasn9226 7 месяцев назад

    This is very usefull thank you

  • @kruan2661
    @kruan2661 Год назад

    supperb!

  • @moonwatcher2001
    @moonwatcher2001 4 года назад

    awesome!!! when harmonic mean?

  • @EchoHeo
    @EchoHeo 6 лет назад

    I love the aesthetics of these videos

  • @mayyousayhd5967
    @mayyousayhd5967 6 лет назад +1

    Mind blown

  • @rasoulkhoshravan5912
    @rasoulkhoshravan5912 4 года назад

    very nice. keep going.

  • @jkoh93
    @jkoh93 6 лет назад

    what if 1 number is -ve? then lhs could be +ve or -ve but rhs would always be imaginary. i think abs(rhs) would be larger than abs(lhs)
    and if both numbers are -ve? lhs would always be -ve and rhs always +ve. but abs both side will satisfy the original inequality

  • @ozgurozmen3378
    @ozgurozmen3378 3 года назад

    nice video

  • @travellcriner6849
    @travellcriner6849 6 лет назад

    Amazing.

  • @mahmoudel-bahnasawi5283
    @mahmoudel-bahnasawi5283 4 года назад

    Awesome ✴️✴️

  • @user-xt3hg6kx2j
    @user-xt3hg6kx2j 5 лет назад

    amazing!

  • @pavelsapehin4308
    @pavelsapehin4308 4 года назад

    The explanation is great, though the music a bit "Silent Hill"-ish :)

  • @brogcooper25
    @brogcooper25 5 лет назад

    What is this type of music called? Links to anything similar?

  • @mohitjani4975
    @mohitjani4975 6 лет назад

    From 3b1b amazing recommendation it was

  • @szturmix
    @szturmix 6 лет назад

    Brilliant! More stuff like that

  • @JoaoVitor-go2ph
    @JoaoVitor-go2ph Год назад

    please come back

  • @vkilgore11
    @vkilgore11 6 лет назад

    Always nice.

  • @ameremortal5715
    @ameremortal5715 6 лет назад

    You rock man how do u get these intuitions

  • @anserali551
    @anserali551 6 лет назад +1

    how h/b = a/h??

  • @farhankarim28
    @farhankarim28 6 лет назад

    Cool, what program for this animation?

  • @tomburns5231
    @tomburns5231 6 лет назад

    Another nice animation, but without explanations these aren't very useful for beginners.

  • @theguythatmakesyoumad3834
    @theguythatmakesyoumad3834 6 лет назад

    This only applies if a+b is equal or greater than 2

  • @ThePharphis
    @ThePharphis 6 лет назад

    before watching: Is it because a square is the maximal way to get an area rather than a rectangle?
    edit: nope, your proof is much more visually appealing. I'm thinking of how to approximate square roots, and modeling them as rectangles is the easiest way to do so (which is why I thought of the comparison). The math also agrees

    • @pedronunes3063
      @pedronunes3063 5 лет назад

      Say that the perimeter is 2p.
      And S=r^2. Any retangle has the area (r+k)(r-k) that equal to r^2 - k^2. So the maximum area is when k=0

    • @pedronunes3063
      @pedronunes3063 5 лет назад

      I think it should be easy to proof visually.

  • @moisesmoises5046
    @moisesmoises5046 6 лет назад

    Now how do we add the harmonic mean?

  • @timmychanson
    @timmychanson 5 лет назад

    what about harmonic mean?

  • @bananaforscale1283
    @bananaforscale1283 4 года назад

    You didn't do it for negative numbers :(

  • @garogarabed6196
    @garogarabed6196 6 лет назад

    those who disliked thought it meant "download"

  • @valorkurzatx
    @valorkurzatx 4 года назад

    My Mind: Booooooooooom

  • @MagicGonads
    @MagicGonads 6 лет назад

    How would one extend this to the general case? (sum of items over n is greater or equal to the 'nth' root of the product of the items where n is the number of items)

    • @ThinkTwiceLtu
      @ThinkTwiceLtu  6 лет назад

      hmm im not sure. let's say we have the diameter split into 3 parts a,b and c. would h be a square root of abc?

    • @MagicGonads
      @MagicGonads 6 лет назад +1

      We don't want a square root of abc, we want a cube root of abc

    • @ThinkTwiceLtu
      @ThinkTwiceLtu  6 лет назад

      ya sorry that's what i mean haha.. so would h be a cube root of abc?

    • @MagicGonads
      @MagicGonads 6 лет назад

      I have no idea, btw I've been working on this
      www.desmos.com/calculator/8zexv8woxa
      The next thing I wanna do is attempt to add ghosts and use the powerup to influence the ghost """AI""" using a summation for the ghost position over time, then I'm gonna add a maze builder type thing so the background matches pacman.
      The last project I completed was
      www.desmos.com/calculator/ikwwzexjpp

    • @ThinkTwiceLtu
      @ThinkTwiceLtu  6 лет назад

      interesting. tbh i have no idea what the second project it about..

  • @محمدحارثبھائی
    @محمدحارثبھائی Год назад

    ..... and where is harmonic mean?

  • @lamalamalex
    @lamalamalex 6 лет назад

    I don’t get it

  • @rishabhdhiman9422
    @rishabhdhiman9422 6 лет назад

    Lol, I still don't get why geometric mean is called geometric mean. It isn't as if it is the only mean with geometric significance.

  • @elliottmcollins
    @elliottmcollins 6 лет назад +1

    What the what is happening at 0:35?

    • @ThinkTwiceLtu
      @ThinkTwiceLtu  6 лет назад +4

      the triangles are similar, so the ratios of sides must be equal. it's all just to show that h = sqrt(ab)

    • @juanfranciscoaleman6938
      @juanfranciscoaleman6938 6 лет назад

      Think Twice sorry for the dumb question but how can you tell they are equal?

    • @juanfranciscoaleman6938
      @juanfranciscoaleman6938 6 лет назад

      Oh nevermind

    • @elliottmcollins
      @elliottmcollins 6 лет назад

      Glad you got it, Juan, but I still don't understand why the triangles are similar.

    • @juanfranciscoaleman6938
      @juanfranciscoaleman6938 6 лет назад +2

      Elliott Collins It took me quite some time, but this is how I figured it out: To be simmilar the triangles need to have the same angles. Lets call the angle on the down left of the triangle "A" and the angle on the down right "B" . At 0:22 imagine the "h" line doesnt exist. In that triangle you can see that the upper angle is 90 degress. That means that A+B has to be 90, because 90 plus the 90 on the upper angle is 180.
      Now we can see that the "h" line breaks the 90 dgs upper angle. But now we see that both triangles now have a 90 degrees angle. Like A and B hasnt changed and A+B=90, AND in the left triangle we see angles A and 90, so what is the other angle:
      A+90+x(the unknown angle)= 180
      A+x=180-90
      A+x=90. >>>>>A+B=90
      So that means x=B
      So the angles of the left triangle are A, 90 and B
      In the right triangle we do the same
      B+90+y(the unknown upper right angle)= 180
      B+y=180-90
      B+y=90 >>>>> B+A=90
      So y=A
      So the angles on the right triangle are also A, B and 90. In conclussion, the triangles are simmilar.
      Sorry if Its not clear, I am not very good at explaining.