Math

I had a lot of fun solving this one, and I think you will too! 0:00 Problem 0:49 Hints 4:12 Solution Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I may receive a
0 Comments
A number of galactic proportions… See more #MegaFavNumbers on this playlist – https://bit.ly/MegaFavNumbers – and read below to contribute your own. More links & stuff in full description below ↓↓↓ See our full collection of video on the sum of three cubes at: http://bit.ly/SumOfCubes (*) the cube (which we depicted quite loosely and artistically, of
0 Comments
Can you solve this geometry problem? Thanks to Lucas from Brazil for the suggestion! Kangaroo Maths 2020 https://www.matematica.pt/en/docs/kangaroo/enunciados/2020/2020_Grade9-10.pdf Proof of inscribed angle theorem https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-inscribed-angles/a/inscribed-and-central-angles-proof Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I
0 Comments
Thanks to Devesh from India for the suggestion! A version of this problem was given in an Olympiad qualifying test. Socratic https://socratic.org/questions/a-root-a-b-root-b-183-a-root-b-b-root-a-182-find-9-5-a-b Math StackExchange https://math.stackexchange.com/questions/2405256/find-the-value-of-frac95ab-given-that-a-sqrtab-sqrtb-183-and-a Brainly https://brainly.in/question/3901575 Quora https://www.quora.com/Suppose-a-b-are-positive-real-numbers-such-that-a%E2%88%9Aa-+-b%E2%88%9Ab-183-a%E2%88%9Ab-+-b%E2%88%9Aa-182-How-do-we-find-9-5-a-+-b Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy
0 Comments
Johnny Ball on the “often missed” Hippocrates of Chios. Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More links & stuff in full description below ↓↓↓ More on Johnny Ball, including his books and live shows: https://www.johnnyball.co.uk See Johnny discuss Russian multiplication: https://youtu.be/HJ_PP5rqLg0 Numberphile is supported by the Mathematical Sciences Research Institute
0 Comments
This challenging geometry problem appeared on one of the hardest math competitions (the Putnam exam), and there is a neat way to solve it! The Putnam Exam has legendary difficulty: the average (median) score is usually 1 out of a possible 120 points. No calculators allowed though, and you have to prove everything very carefully.
0 Comments
Can you solve this incredibly difficult calculus question? I had a lot of fun solving this one! Special thanks this month to: Kyle, Mike Robertson, Michael Anvari. Robert Zarnke, Fiona Harper. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Adapted from Comment from discussion PhysicsHelpBernoulli’s comment from discussion "[12th grade math] What number would n have
0 Comments
Can you solve this geometry brain teaser? Note: I was emailed a similar problem but I am unable to locate the original source. It seems to be in the style of Bright Side quizzes, but often those are based on problems circulating. Please let me know if can identify the original source and I will
0 Comments
The ancient Babylonians used a number system with base 60 (sexagesimal). More links & stuff in full description below ↓↓↓ Tablet image courtesy of Bill Casselman and Yale Babylonian Collection – more at http://www.math.ubc.ca/~cass/Euclid/ybc/ybc.html This video features Thomas Woolley – he tweets at https://twitter.com/#!/thomasewoolley NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe:
0 Comments
John H Conway on his love/hate relationship with his most “famous” invention. Conway playlist: http://bit.ly/ConwayNumberphile More on how he invented it at: http://youtu.be/R9Plq-D1gEk More links & stuff in full description below ↓↓↓ Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Numberphile is supported by the Mathematical
0 Comments
More links & stuff in full description below ↓↓↓ Brady’s Movember Page: http://bit.ly/BradyMo See full description for list of Connect 4 links. John Tromp’s page: http://bit.ly/TrompNumberphile James Allen’s Connect Four book: http://bit.ly/AllenBook James Allen: http://james.fabpedigree.com/ OEIS: https://oeis.org/A212693 Victor Allis paper: http://bit.ly/AllisPaper NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by
0 Comments
George Dantzig, William Sidis, Srinivasa Ramanujan? Who was the real Good Will Hunting? More links & stuff in full description below ↓↓↓ Maths in Good Will Hunting: http://www.youtube.com/watch?v=iW_LkYiuTKE This video features Numberphile’s very own mathematics superstar – Dr James Grime. NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by Brady
0 Comments
Can you solve this interesting geometry problem? References Solution by “WAY TO GOVT JOB” on YouTube Stretched length of band https://www.thestudentroom.co.uk/showthread.php?t=1936482 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I may receive a
0 Comments
It’s not so simple to solve for this simple answer. Thanks to all patrons! Special thanks this month to: Richard Ohnemus, Michael Anvari, Shrihari Puranik, Kyle. WolframAlpha Get Real with Wolfram|Alpha—Computing Roots https://www.wolframalpha.com/input/?i=cuberoot(8%2B3*sqrt(21))%2Bcuberoot(8-3*sqrt(21)) https://www.wolframalpha.com/input/?i=(8%2B3*sqrt(21))%5E(1%2F3)%2B(8-3*sqrt(21))%5E(1%2F3) Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Playlist to watch all videos on MindYourDecisions: https://www.youtube.com/playlist?list=UUHnj59g7jezwTy5GeL8EA_g This is the only channel to feature math topics suggested by
0 Comments
Tadashi’s back (for the final video in this mini series) demonstrating the Kendama and some angular momentum. More links & stuff in full description below ↓↓↓ Tadashi Tokieda will be back on Numberphile soon. Here’s a playlist of his videos: http://bit.ly/tadashi_vids Kendama also known as bilboquet or boliche or bolero. Video by Brady Haran and
0 Comments
Fermat’s “Little” Theorem is great – but beware of Fermat Liars and tricky Carmichael Numbers. More links & stuff in full description below ↓↓↓ Continues at: http://youtu.be/HvMSRWTE2mI Featuring Dr James Grime – https://twitter.com/jamesgrime Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Numberphile is supported by the
0 Comments
Neil Sloane discusses peaceable queens and chess. Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More links & stuff in full description below ↓↓↓ Learn more at the OEIS entry (loads of links): https://oeis.org/A250000 References: Ainley, Stephen. Mathematical Puzzles. London: G Bell & Sons, 1977. Yukun Yao and Doron Zeilberger, Numerical and
0 Comments
Can you solve for the area of the square and the length of the tangent line? Special thanks this month to Fiona Harper, Kyle, Mike Robertson, Michael Anvari, Robert Zarnke. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Adapted from a puzzle by Twitter @Cshearer41 (Catriona Agg) A semicircle and quarter circle inside a square. How
0 Comments
Tadashi Tokieda is back, this time with Moiré Patterns. More with Tadashi: http://bit.ly/tadashi_vids More links & stuff in full description below ↓↓↓ Out thanks also to our Patreon supporters, especially: Jeff Straathof Ken Baron Today I Found Out Roman Urbanovski Joanna & Mehdi Christian Cooper Peggy Y John Buchan Bill Shillito Andrzej ‘Yester’ Fiedukowicz Ripta
0 Comments
Professor Ron Graham discusses the famed Happy Ending Problem and Ramsey Theory. More Ron Graham Videos: http://bit.ly/Ron_Graham More links & stuff in full description below ↓↓↓ An extra little bit at: http://youtu.be/hnIBiIcuudU Graham’s Number: http://youtu.be/XTeJ64KD5cg Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Numberphile is supported
0 Comments
This problem went viral after it appeared on a Math Olympiad test for talented students in Singapore. It’s not a trick question! Here’s the problem, which I have very slightly re-worded for clarity. Blog post (detailed text explanation): http://mindyourdecisions.com/blog/2015/04/14/when-is-cheryls-birthday-answer-to-viral-math-puzzle/ Source: https://www.facebook.com/kennethjianwenz/photos/a.173663129479243.1073741827.167504136761809/385751114937109/?type=1&theater Official Solution: http://mothership.sg/2015/04/p5-logic-question-is-actually-a-math-olympiad-question-for-sec-3-and-4-students/ Albert and Bernard have just become friends with Cheryl, and they
0 Comments
This is a fun little geometry problem! DataGenetics http://datagenetics.com/blog/november22016/index.html How to solve the shape-shifting triangle Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I consider all ideas though can’t always reply! Why are some comments before the video is published? Get early access and support the channel on Patreon https://www.patreon.com/mindyourdecisions If you buy
0 Comments
Tadashi Tokieda cuts various combinations of loops and Mobius loops – with surprising results. More links & stuff in full description below ↓↓↓ Part 2: https://youtu.be/mh3eMt09EAs And more: http://bit.ly/tadashi_vids Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Numberphile is supported by the Mathematical Sciences Research Institute
0 Comments
Can you solve this challenging problem from the Mathematical Olympiad of Singapore? Thanks to Truong from Vietnam for the suggestion! Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I cannot reply to everyone but I consider all ideas! Like many YouTubers I use popular software to prepare my videos. You can search for
0 Comments
Why number 1 is the “leading digit” more often than you may expect? More links & stuff in full description below ↓↓↓ See us test the law using Brady’s YouTube viewing figures at: http://youtu.be/VbtNy54ya9A Blog about all this at: http://bit.ly/benfordslaw Brown Paper from this video on ebay: http://bit.ly/brownpapers This video features Steve Mould: http://www.stevemould.com/ and
0 Comments
This is a really fun geometry problem. It comes from the UKMT, a test which is part of forming the Olympiad team in the UK. Thanks to Liam for sending it to me! Can you figure it out? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Playlist to watch all videos on MindYourDecisions: https://www.youtube.com/playlist?list=UUHnj59g7jezwTy5GeL8EA_g This is the only channel to feature
0 Comments
Part Two of Golden Ratio Trilogy Proof that an infinite number of sequences have that “golden ratio” property – not just the Fibonacci Numbers. More links & stuff in full description below ↓↓↓ Next in the trilogy: http://youtu.be/PeUbRXnbmms Matt’s signed book (& extra goodies): http://bit.ly/Matt_Signed Amazon (UK): http://bit.ly/Matt_4D_UK Amazon (US): http://bit.ly/Matt_4D_US All links to videos
0 Comments
This is the higher quality version of how to multiply numbers by drawing lines. Get the Multiply By Lines Book! http://amzn.to/XRm7M4 If you like my videos, you can support me at Patreon: https://www.patreon.com/mindyourdecisions Connect on social media. I update each site when I have a new video or blog post, so you can follow me
0 Comments
Brady Numbers T-Shirt: http://bit.ly/T-Shirt-BN Part One of Golden Ratio Trilogy More links & stuff in full description below ↓↓↓ The new “Brady Sequence” demonstrates why Fibonacci Numbers are not so special. Featuring Matt Parker. Next in the trilogy: http://youtu.be/dTWKKvlZB08 Matt’s signed book (& extra goodies): http://bit.ly/Matt_Signed Amazon (UK): http://bit.ly/Matt_4D_UK Amazon (US): http://bit.ly/Matt_4D_US Discuss this video
0 Comments
Many tests around the world include a problem like this. How can you calculate this quickly, without making any mistakes? Thanks to all patrons! Special thanks to: Ertugrul Oruç, Michael Anvari, Richard Ohnemus, Shrihari Puranik, Kyle. Source https://twitter.com/thebapex/status/1149020375189270528 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I consider all ideas though can’t always
0 Comments
First in a series of videos about knots. Here we have Carlo H. Séquin from UC Berkeley. More links & stuff in full description below ↓↓↓ More videos to come at: http://bit.ly/Knot-a-Phile Edit and animation by Pete McPartlan. Film and interview by Brady Haran With thanks to Rob Scharein for the use of his software
0 Comments
The 80/20 rule or Pareto principle comes up a lot in economics and business. But why does this pattern emerge? I show why using a paper clip experiment. Note: VSauce later made a video about Zipf’s law that uses this same experiment but does the math incorrectly. The long tail should be for the single
0 Comments
Banks, Facebook, Twitter and Google use epic numbers – based on prime factors – to keep our Internet secrets. This is RSA public-key encryption. More links & stuff in full description below ↓↓↓ Gold Vault: https://youtu.be/CTtf5s2HFkA This video features Dr James Grime (http://singingbanana.com/). Message from James: “Thanks to Dr Chris Hughes of the University of
0 Comments
The Prisoner’s Dilemma is the most famous problem in game theory, as it shows that individuals who make rational decisions might end up in an outcome that’s worse for everyone in the group. In other words, individual rationality does not imply group rationality. Watch a higher quality version of this video: https://www.youtube.com/watch?v=TJCGTNIwmv8 You can also
0 Comments
The Josephus Problem, featuring Daniel Erman from University of Wisconsin-Madison. Winning at Dots and Boxes: https://youtu.be/KboGyIilP6k More links & stuff in full description below ↓↓↓ Correction: Around 9:40 that should be L less than 2^a NOT 2a — Sorry, typo in editing! But you got the point hopefully. Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website:
0 Comments
Can you solve this tricky math problem? Thanks to Asad for the suggestion! Art of Problem Solving 2019 AIME Problem 3 (there are many solution methods) https://artofproblemsolving.com/wiki/index.php/2019_AIME_I_Problems/Problem_3 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I cannot reply to everyone but I consider all ideas! Like many YouTubers I use popular software to
0 Comments
The Dynamical Uniform Boundedness Conjecture with Dr Holly Krieger. Extra from this interview: https://youtu.be/v4LWFzTyhpU Dr Krieger on the Numberphile Podcast: https://youtu.be/QmfQQzjpdpM More links & stuff in full description below ↓↓↓ More videos with Holly: http://bit.ly/HollyKrieger Holly’s website: https://www.dpmms.cam.ac.uk/~hk439/ She is the Corfield Lecturer at the University of Cambridge as well as a Fellow at Murray
0 Comments
Thanks to Taka for the suggestion! This is a fun and challenging geometry problem. Special thanks this month to: Michael Anvari, Kyle. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Source What's the width of the rectangle?#geometry #maths #puzzle pic.twitter.com/FPOod0dKrB — pangolin (@panbtc) February 25, 2020 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video).
0 Comments
Is 1 a prime number? Apparently not. Dr James Grime explains. More links & stuff in full description below ↓↓↓ James Grime’s website is: http://singingbanana.com/ NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by Brady Haran Patreon: http://www.patreon.com/numberphile Brady’s videos subreddit: http://www.reddit.com/r/BradyHaran/ Brady’s latest videos across all channels: http://www.bradyharanblog.com/ Sign
0 Comments