Math

This is one of the harder calculus problems I’ve come across. Thanks to Nguyen Huynh Khoi from Vietnam for the suggestion! Solution from https://khoahoc.vietjack.com/question/84520/cho-ham-so-f-x-co-dao-ham-va-lien-tuc-tren-doan-4-8 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 purchase through these links, I may

This is a visual way to understand Brahmagupta’s quadratic formula. #Shorts Song Credits Song: Kajra Re Singers: Alisha Chinai, Shankar Mahadevan, Javed Ali Music: Shankar-Ehsaan-Loy Lyrics: Gulzar Lucas Vieira animation https://www.tumblr.com/1ucasvb/42739093986/completing-the-square https://en.wikipedia.org/wiki/File:Completing_the_square.gif Cornell Mathematics professor David W. Henderson: Geometric Solutions of Quadratic and Cubic Equations. https://pi.math.cornell.edu/~dwh/papers/geomsolu/geomsolu.html But Why? Intuitive Mathematics (Archived) https://web.archive.org/web/20160821053459/https://sites.google.com/site/butwhymath/algebra/the-quadratic-formula MindYourDecisions posts The

This equation has a secret meaning. #shorts 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 commission for sales. (As an Amazon Associate I earn from qualifying purchases.) This has

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

We’re exploring the world of Chicken Nuggets and Frobenius numbers. 43 has long been a special number in the world of McNugget mathematics, but 11 is also important! More links & stuff in full description below ↓↓↓ This video features Dr James Grime – https://twitter.com/jamesgrime NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile

Thanks to http://www.audible.com/numberphile More links & stuff in full description below ↓↓↓ Here’s the paper Dr Grime discusses: http://arxiv.org/pdf/1101.4470.pdf OEIS: http://oeis.org Dr Grime: http://singingbanana.com 1729: http://youtu.be/LzjaDKVC4iY 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/

There’s an incredible method to calculate the square root of a perfect square in your head. MIT Entrace Exam Arithmetic 1876 WayBackMachine: https://web.archive.org/web/20190404065722/https://libraries.mit.edu/archives/exhibits/exam-entrance1876/arithmetic1876.html Square root method Burning Math http://burningmath.blogspot.com/2013/09/extracting-square-roots-mentally-at.html Square root method proof Math StackExchange https://math.stackexchange.com/questions/2069192/why-does-this-method-for-finding-the-square-root-of-a-number-work Square root method Grey Matters http://gmmentalgym.blogspot.com/2010/10/root-extractions.html#rtsqr Hindu-Arabic numeral system https://en.wikipedia.org/wiki/Hindu%E2%80%93Arabic_numeral_system Laplace quote https://en.wikipedia.org/wiki/History_of_the_Hindu%E2%80%93Arabic_numeral_system#Impact_on_arithmetic Laplace picture https://en.wikipedia.org/wiki/File:Laplace,_Pierre-Simon,_marquis_de.jpg Abacus picture https://en.wikipedia.org/wiki/Abacus#/media/File:Houghton_Typ_520.03.736_-_Margarita_philosophica.jpg

Thanks to Matej for suggesting this problem! This is from a math competition for 14 year olds in Croatia. While the problem is challenging, “you should be able to solve it” using elementary geometry and algebra. 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

In the past 5 months, all of Mark Rober’s videos have been #1 trending on YouTube. He put his success in perspective by analogy to a statistical experiment of flipping coins. Some people pointed out the calculation wasn’t quite correct, so I thought it would be a great topic for a video. Mark Rober tweet

Our Pi Playlist (more videos): http://bit.ly/PiPlaylist Steve Mould (tau) and Matt Parker (pi) go head-to-head. More links & stuff in full description below ↓↓↓ See our tau video: http://www.youtube.com/watch?v=83ofi_L6eAo And check our Pi videos: http://www.youtube.com/playlist?list=PL4870492ACBDC2E7C Matt Parker: http://www.standupmaths.com/ Steve Mould: http://www.stevemould.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

In 1880, James Garfield contributed a new proof of geometry’s most famous right triangle theorem. Mathematical treasure: Garfield’s proof https://www.maa.org/press/periodicals/convergence/mathematical-treasure-james-a-garfields-proof-of-the-pythagorean-theorem Engraved portrait https://en.wikipedia.org/wiki/File:GARFIELD,_James_A-President_(BEP_engraved_portrait).jpg Gizmodo post https://gizmodo.com/james-garfield-was-the-only-u-s-president-to-prove-a-m-1037750658 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 purchase through these links,

This is a standard question to prepare for India’s famously challenging JEE Advanced exam. Here is one way to solve the question quickly. Thanks to Avinash for the suggestion! Special thanks this month to: Daniel Lewis, Robert Zarnke, Kyle, Mike Robertson. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Problem credit to David Altizio (section 3

Why five-sided figures pose a problem from Professor John Hunton – and a bit about the importance of Penrose Tiling. More links & stuff in full description below ↓↓↓ Professor Hunton works at the University of Leicester. 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

A tetrahedron and a pyramid have edges of equal length. If they are glued together on a triangular face with the vertices aligned, how many faces will the new shape have? This question is trickier than it looks! It stumped the test-makers. Playable demonstration: Steve Phelps has made a Geogebra worksheet that you can try

There are 25 mechanical horses and a single racetrack. Each horse completes the track in a pre-programmed time, and the horses all have different finishing times, unknown to you. You can race 5 horses at a time. After a race is over, you get a printout with the order the horses finished, but not the

Can you solve this problem that stumped many advanced math students? References https://io9.gizmodo.com/ready-this-simple-puzzle-once-stumped-96-of-americas-1698814691 https://www.theguardian.com/science/2017/jun/05/did-you-solve-it-are-you-in-the-smartest-10-per-cent https://www.mapleprimes.com/posts/206713-Puzzle-Or-A-Simple-Exercise http://puzzles.nigelcoldwell.co.uk/seventytwo.htm https://timss.bc.edu/timss1995i/TIMSSPDF/C_full.pdf 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! Like many YouTubers I use popular software to prepare my videos. You can search for animation software tutorials on YouTube

Thanks to Juanci for the suggestion! Also thanks to everyone who shared a solution on Twitter. A special thanks to LuisAndrRomero2 who provided the first detailed solution. Special thanks this month to: Michael Anvari, Kyle. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Who can solve this one? I'm working on a video for it and

Colin Rizzio became famous after finding a mistake on the S.A.T. Sources https://www.deseret.com/1997/2/7/19293720/math-question-on-the-sat-didn-t-sit-well https://people.com/archive/flunking-the-tester-vol-47-no-7/ https://www.nytimes.com/1997/02/07/us/student-proves-that-sat-can-be-d-wrong.html https://www.chicagotribune.com/news/ct-xpm-1997-02-07-9702070268-story.html https://www.dartmouth.edu/~chance/chance_news/recent_news/chance_news_6.03.html 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! Like many YouTubers I use popular software to prepare my videos. You can search for animation software tutorials on YouTube

Thanks to Dhrubajyoti for the suggestion! A similar problem was asked to class 10 students in India (Q33 from SMO junior 2016). I admit that this one stumped me. Can you figure it out? Solution presented: post by Thomas Hill on Quora https://www.quora.com/In-a-triangle-ABC-AB-AC-angle-BAC-100-circ-Let-D-be-a-point-such-that-B-is-an-interior-point-of-AD-and-AD-BC-How-can-you-find-angle-BDC Other solutions http://jwilson.coe.uga.edu/EMT668/EMT668.Folders.F97/Rapley/EMT725/100deg/100deg.html http://jwilson.coe.uga.edu/EMT668/EMAT6680.F99/Wise/essay1/essay1.htm https://gogeometry.blogspot.com/2011/11/problem-685-isosceles-triangle-100-40.html pic.twitter.com/NNSkNX2I5w — José Luis da Vila (@jldavilaa01)

Large factorials and the use of Stirling’s Approximation. Featuring Professor Ken McLaughlin. More links & stuff in full description below ↓↓↓ Professor McLaughlin is based at Colorado State University: https://www.math.colostate.edu/~kenmcl/ We filmed this during his time at the Mathematical Sciences Research Institute. 69 Factorial: https://www.youtube.com/watch?v=kw6l_uTakRA Numberphile is supported by the Mathematical Sciences Research Institute (MSRI):

Thanks to Ryan from India for the suggestion! Two candles of equal height but different thickness are lit. The first burns off in 8 hours and the second in 10 hours. When will the first candle be half the height of the second? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many

A compilation of Numberphile sound checks – Brady typically asks “what did you have for breakfast” so he can monitor audio levels. More links & stuff in full description below ↓↓↓ Previous sound checks with scientists here: http://youtu.be/4anqDfgQneA 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

Thanks to Amit from India for the suggestion! A circle is tangent on the exterior of a side of a triangle and tangent to the lines through the other two sides. The tangent side length 7, and the other side lengths are 8 and 9. What is the radius of the circle? 0:00 Problem 1:22

Can you solve this fun little geometry puzzle? Thanks to Roman for the suggestion! 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 commission for sales. (As an Amazon Associate

Matt Parker explores the work of William Shanks – and boots up the ShanksBot. More links & stuff in full description below ↓↓↓ Matt Parker’s 2022 Pi Day Video: https://youtu.be/dtiLxLrzjOQ Discussing William Shanks on Objectivity: https://youtu.be/7yTXMeiVBCc Prime Number playlist: https://bit.ly/PrimePlaylist Pi playlist: http://bit.ly/PiPlaylist Matt Parker website: https://standupmaths.com Numberphile is supported by the Mathematical Sciences Research

A 6’28” version of our “Pi with Pies” calculation. More links & stuff in full description below ↓↓↓ Videos features Matt Parker who tweets at https://twitter.com/standupmaths The Pi-inspired music in the video explained: http://periodicvideos.blogspot.co.uk/2013/03/pimusic.html Our full collection of Pi videos at http://bit.ly/W4oDN1 While the pies are usually delicious, this batch was not for consumption (even

Thanks to Victor for the suggestion! A version of this problem appeared on a Kangaroo math competition for 12-13 year olds. Can you figure it out? Special thanks this month to: Michael Anvari, Daniel Lewis, Robert Zarnke, Kyle, Mike Robertson. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Original Math Kangaroo question on YouTube Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1

Our Pi Playlist (more videos): http://bit.ly/PiPlaylist How accurately can we calculate Pi using hundreds of REAL pies? More links & stuff in full description below ↓↓↓ Extended version of this video (director’s slice) at http://www.youtube.com/watch?v=x4kyFKyCMv0 This video features Matt Parker: https://twitter.com/standupmaths Matt believes this is the world’s most accurate pie-based Pi calculation. More Pi videos:

People around the world have asked me this and similar problems. Learn how to solve using only geometry (and a little bit of algebra). There are many other ways to solve the problem too https://www.mathalino.com/reviewer/plane-geometry/02-area-common-arcs-quarter-circles 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! Like many

17 is the minimum number of clues required to give a unique sudoku solution – but how did mathematicians prove this? Featuring James Grime. More links & stuff in full description below ↓↓↓ Dr James Grime discusses a recent paper which cracked the problem. The paper being discussed by McGuire and others is at http://arxiv.org/abs/1201.0749