Nerd Paradise : Divisibility Rules for Arbitrary Divisors It's rather obvious when a number is divisible by 2 or 5, and some of you probably know how to tell if a number is divisible by 3, but it is possible to figure out the division 'rule' for any number. Here are the rules for 2 through 11... The last digit is divisible by 2. The sum of all the digits in the number is divisible by 3. The last 2 digits are divisible by 4. The last digit is 5 or 0. The number is both divisible by 2 and divisible by 3. Cut the number into 2 parts: the last digit and everything else before that. The last 3 digits are divisible by 8 The sum of all the digits in the number is divisible by 9. The last digit is a 0. Break the number into two parts (like you did for the division by 7 rule). Also there is a quick way for determining divisibility by 11 for 3-digit numbers: If the inner digit is larger than the two outer digits, then it is divisible by 11 if the inner digit is the sum of the two outer digits. Rules for all divisors ending in 1... User Comments: 9 Dividing By 12
Brain Explorer Why Nikola Tesla was the greatest geek who ever lived Additional notes from the author: If you want to learn more about Tesla, I highly recommend reading Tesla: Man Out of Time Also, this Badass of the week by Ben Thompson is what originally inspired me to write a comic about Tesla. Ben's also got a book out which is packed full of awesome. There's an old movie from the 80s on Netflix Instant Queue right now about Tesla: The Secret of Nikola Tesla. It's corny and full of bad acting, but it paints a fairly accurate depiction of his life.
6174 (number) 6174 is known as Kaprekar's constant[1][2][3] after the Indian mathematician D. R. Kaprekar. This number is notable for the following property: Take any four-digit number, using at least two different digits. 9990 – 0999 = 8991 (rather than 999 – 999 = 0) 9831 reaches 6174 after 7 iterations: 8820 – 0288 = 8532 (rather than 882 – 288 = 594) 8774, 8477, 8747, 7748, 7487, 7847, 7784, 4877, 4787, and 4778 reach 6174 after 4 iterations: Note that in each iteration of Kaprekar's routine, the two numbers being subtracted one from the other have the same digit sum and hence the same remainder modulo 9. Sequence of Kaprekar transformations ending in 6174 Sequence of three digit Kaprekar transformations ending in 495 Kaprekar number Bowley, Rover. "6174 is Kaprekar's Constant".
Weierstrass functions Weierstrass functions are famous for being continuous everywhere, but differentiable "nowhere". Here is an example of one: It is not hard to show that this series converges for all x. Here's a graph of the function. You can see it's pretty bumpy. Below is an animation, zooming into the graph at x=1. Wikipedia and MathWorld both have informative entries on Weierstrass functions. back to Dr.
Role Playing Games - Free Multiplayer Online Games Astro Lords is an MMORPG/Strategy set in a sci-fi universe. Players control an asteroid, construct and upgrade buildings and fight with others to gain control over the Oort cloud. The game can be played on iOS, Android and desktop devices. Players might be positively appalled by the lack of character customization, but that is more than compensated by the fact that eventually you can move your base, perhaps towards the members of your alliance, or the enemy if you feel you can gain an edge. The combat has players duke it out in turn-based combat with spaceships in the vast void. It takes quite some skill and provides ample entertainment, because the fights involve dodging slow-moving projectiles (there are lasers too!) Astro Lords is definitely a promising title, but the strategy elements could very well be executed better. See Videos Free, with option to pay for additional features. Play Astro Lords now!
Free Lectures Online Whether your goal is to earn a promotion, graduate at the top of your class, or just accelerate your life, lectures can help get you there. Our archives of lectures cover a huge range of topics and have all been handpicked and carefully designed by experienced instructors throughout the world who are dedicated to helping you take the next step toward meeting your career goals. Lifelong learns can turn their free time turn into self-improvement time. The online lectures on this list are more than lecture notes or a slideshow on a topic -- they were designed for audiences like you, with carefully sequenced themes and topics taught by veteran educators, and often with additional resources for your own independent study. Lecture courses are a valid and vital learning tool, and may be one of the best methods of learning available.
La collection du musée virtuel Frédéric Back - Frédéric Back, agir ensemble Vous aurez besoin du plugiciel Flash qui vous permettra de voir les vidéos et agrandir les oeuvres. Cliquez ici pour le télécharger. Copyright © Frédéric Back, Tous droits réservés, 2010 Dernière mise à jour : 2010-10-15 | Conditions d’utilisation - StumbleUpon The length of the polygonal spiral is found by noting that the ratio of inradius to circumradius of a regular polygon of sides is The total length of the spiral for an -gon with side length is therefore Consider the solid region obtained by filling in subsequent triangles which the spiral encloses. -gons of side length , is The shaded triangular polygonal spiral is a rep-4-tile.
Cranial Nerves Can't remember the names of the cranial nerves? Here is a handy-dandy mnemonic for you: On Old Olympus Towering Top AFamous Vocal German Viewed Some Hops. The bold letters stand for: olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, spinal accessory, hypoglossal. Still can't remember the cranial nerves?