VERY HARD South Korean Geometry Problem (CSAT Exam)
1.3 میلیون بار بازدید -
6 سال پیش
-
Thanks to Hyeong-jun (H. J.)
Thanks to Hyeong-jun (H. J.) for emailing me this problem! This is a challenging problem from the math section of the 1997 CSAT, a standardized test in South Korea. Can you figure it out? It took me several attempts, but it was really satisfying when I solved it (I did need to look up one key insight, which is the first thing presented in the solution). So give it a try, and don't peek at the rest of the solution too early!
0:00 Problem
1:58 My many attempts
3:28 Unwrapping a cone
5:14 Solution
Coordinate geometry solution and proof of uphill/downhill track
https://www.desmos.com/calculator/l18...
Note: pretty much every time I said or wrote "circular arc" I meant to say or write "circular sector." A "circular arc" is a portion of a circle's circumference; a "circular sector" is the enclosed region between the arc and two radii.
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"Math Puzzles Volume 2" is a sequel book with more great problems. (rated 4.3/5 stars on 4 reviews)
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"40 Paradoxes in Logic, Probability, and Game Theory" contains thought-provoking and counter-intuitive results. (rated 4.3/5 stars on 12 reviews)
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"The Best Mental Math Tricks" teaches how you can look like a math genius by solving problems in your head (rated 4.7/5 stars on 4 reviews)
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"Multiply Numbers By Drawing Lines" This book is a reference guide for my video that has over 1 million views on a geometric method to multiply numbers. (rated 5/5 stars on 3 reviews)
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0:00 Problem
1:58 My many attempts
3:28 Unwrapping a cone
5:14 Solution
Coordinate geometry solution and proof of uphill/downhill track
https://www.desmos.com/calculator/l18...
Note: pretty much every time I said or wrote "circular arc" I meant to say or write "circular sector." A "circular arc" is a portion of a circle's circumference; a "circular sector" is the enclosed region between the arc and two radii.
Can You Solve This 6th Grade Geometry Problem From China? (1.7 million views)
How To Solve For The Area. Viral Home...
HARD Geometry Problem: Can You Solve The Horse Grazing Puzzle? (165,000 views)
HARD Geometry Problem: Can You Solve ...
Can You Solve A REALLY HARD Math Problem? The Circle Inscribed In A Parabola Puzzle (83,000 views)
Can You Solve A Challenging Calculus ...
My blog post for this video
https://wp.me/p6aMk-7UJ
If you like my videos, you can support me at Patreon:
Patreon: mindyourdecisions
Connect on social media. I update each site when I have a new video or blog post, so you can follow me on whichever method is most convenient for you.
My Blog: https://mindyourdecisions.com/blog/
Twitter: Twitter: preshtalwalkar
Facebook: Facebook: 168446714965
Google+: https://plus.google.com/1083366085665...
Pinterest: Pinterest: preshtalwalkar
Tumblr: Tumblr: preshtalwalkar
Instagram: Instagram: preshtalwalkar
Patreon: Patreon: mindyourdecisions
Newsletter (sent only for big news, like a new book release): http://eepurl.com/KvS0r
If you buy from the links below I may receive a commission for sales. This has no effect on the price for you.
My Books
"The Joy of Game Theory" shows how you can use math to out-think your competition. (rated 3.9/5 stars on 32 reviews)
http://amzn.to/1uQvA20
"The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias" is a handbook that explains the many ways we are biased about decision-making and offers techniques to make smart decisions. (rated 4.6/5 stars on 3 reviews)
http://amzn.to/1o3FaAg
"Math Puzzles Volume 1" features classic brain teasers and riddles with complete solutions for problems in counting, geometry, probability, and game theory. Volume 1 is rated 4.4/5 stars on 13 reviews.
http://amzn.to/1GhUUSH
"Math Puzzles Volume 2" is a sequel book with more great problems. (rated 4.3/5 stars on 4 reviews)
http://amzn.to/1NKbyCs
"Math Puzzles Volume 3" is the third in the series. (rated 3.8/5 stars on 5 reviews)
http://amzn.to/1NKbGlp
"40 Paradoxes in Logic, Probability, and Game Theory" contains thought-provoking and counter-intuitive results. (rated 4.3/5 stars on 12 reviews)
http://amzn.to/1LOCI4U
"The Best Mental Math Tricks" teaches how you can look like a math genius by solving problems in your head (rated 4.7/5 stars on 4 reviews)
http://amzn.to/18maAdo
"Multiply Numbers By Drawing Lines" This book is a reference guide for my video that has over 1 million views on a geometric method to multiply numbers. (rated 5/5 stars on 3 reviews)
http://amzn.to/XRm7M4
6 سال پیش
در تاریخ 1397/01/08 منتشر شده
است.
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