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Showing posts from July, 2018

Problem of the Week 7-26-18: 2nd Order Nonhomogenous Linear Differential Equation [Differential Equations]

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Check out this Problem of the Week. Be sure to let us know how you solved it in the comments below or on social media! Solution below: Video:

Problem of the Week 7-19-18: Invertible Matrix [Linear Algebra]

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Check out this Problem of the Week. Be sure to let us know how you solved it in the comments below or on social media! Solution below: Video: *Note: In the video, k 2  - 1 - 6( k -  1) reduces to  k 2 - 6 k + 5 NOT  k 2  - 6 k  - 5

Unlucky Numbers Around the World

via GIPHY Friday the 13 th is upon us!  Across the nation, there are people avoiding black cats, spilled salt, ladders, and broken mirrors. Not everyone, however, is scared of 13 because they have other numbers to fear.  In honor of today, here are 6 unlucky numbers from around the world. 4 -  China In  China , the  number 4  is considered unlucky because it is homophonous to the word "death." Similar to how the 13 th floor is absent in many buildings in the West, the 4 th floor is often left out in China. 9 - Japan Just like the number 4 in China, the number 9 is a bad omen in Japan because it sounds similar to the Japanese word for “torture.” 17 - Italy The Roman numeral for 17 is  XVII, and an  anagram for XVII is "VIXI.” This translates to “I lived," aka “my life is over." 26  - India  For India, tragedies and disasters have the pattern of striking on the 26 th ( the 2008 Mumbai terror attack, the 2001 Gujarat earthquake, the 2004 Indian Ocean tsun

Advanced Knowledge Problem of the Week 7-12-18: Root Existence for a Polynomial [Real Analysis]

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Check out this Advanced Knowledge Problem of the Week. Be sure to let us know how you solved it in the comments below or on social media! Solution below. Solution Video

Problem of the Week 7-10-18: A Functional Equation on Nonnegative Integers [Functional Equations]

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Check out this Problem of the Week. Be sure to let us know how you solved it in the comments below or on social media! Solution below. Solution Video

Advanced Knowledge Problem of the Week 7-5-18: Infinite Squares and Euler's Totient Function [Number Theory]

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Check out this Advanced Knowledge Problem of the Week. Be sure to let us know how you solved it in the comments below or on social media! Solution below. Solution Video

Problem of the Week 7-3-18: Invariant Sums of Digits [Number Theory]

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Check out this Problem of the Week. Be sure to let us know how you solved it in the comments below or on social media! Solution below. Solution Video