Henry Swanson
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 11h comment Fast method to pick random numbers? If you're drawing a large number of cards, shuffling isn't any slower than drawing randomly, because once you've shuffled, you just need to iterate through the array. You'll still need to make $n$ random picks, but now they're all at the beginning, instead of spaced out. Apr1 answered Are all functions that have an inverse bijective functions? Mar25 awarded Enlightened Mar20 answered explaining $|a+b|≤|a|+|b|$ in simple terms Mar10 comment Paradox: Is $1 \in (0,1)$? Nothing is wrong about representing them as decimals. You have the clause "they are not all zero (or else $x = 0$)." There is a similar clause you should also add: "they are not all nine (or else $x = 1$)". Mar8 comment Given two potatoes, prove that there is a loop of wire which fits around both Unfortunately, my geometric proofs are a lot worse than my geometric intuition. How would one prove that? You'd have to somehow avoid the case where two flat sides of the potatoes are flush against each other, which seems hard. Mar8 awarded Nice Answer Mar8 answered Given two potatoes, prove that there is a loop of wire which fits around both Mar6 awarded Nice Answer Mar6 revised Tetrahedron and Sphere added 8 characters in body Mar6 comment Tetrahedron and Sphere Whoops, I did mean that. Thanks. Mar6 comment What are some real life applications of limits? Limits are how you make "infinitesimal" rigorous. Without it, it's very hard to define derivatives and integrals, which are the cornerstones of physics. Mar6 answered Tetrahedron and Sphere Mar4 comment Solving the equation $-5a = 15$: is it possible to multiply a negative number by a positive and make it positive? Who says $a$ is positive? Feb16 comment On groups of four elements Which element is the identity? Keep in mind that no two of $a$, $b$, $c$, and $d$ are equal. Once you know which it is, think about the pairs of inverses. Jan30 comment Why is n mod 0 undefined? The trick is "a divided by b" vs "b divides a". The latter is defined as "there exists an $x$ such that $bx = a$". But the former is defined only when that $x$ is unique (because it returns that $x$). So even though $0/0$ is undefined, $0 \mid 0$, because there exists an $x$ such that $0x = 0$ (every $x$, actually). But zero doesn't divide anything else, because $0x$ is always zero. Jan28 revised Requirement That a Vector be Related to Itself Through Identity added 353 characters in body Jan28 answered Requirement That a Vector be Related to Itself Through Identity Jan13 answered How to resemble hyperbolic trigonometric functions (HTF) from normal trigonometric functions(NTF)?? Jan8 awarded Yearling