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Sep 15, 2021 · The phrase "neon number" is sometimes used for a number where: square the number, add the digits of that in base 10, and you get the original number. So, 9 is a neon number (-> 81, 8+1, 9) Indeed it is usually said there are only three neon numbers (0, 1, and 9). Surprisingly I couldn't google any proof of this.
One way is to convert the complex number into polar form. For z = reiθ, z2 = r2ei (2θ). So to take the square root, you'll find z1 / 2 = ± √reiθ / 2. Added: Just as with the nonnegative real numbers, there are two complex numbers whose square will be z. So there are two square roots (except when z = 0). Share.
Dec 13, 2016 · 1 Answer. Sorted by: 1. 241 241 is prime, so it's only divisible by the sum of its base n n digits if that sum is 1 1 (which means n = 241 n = 241) or 241 241 (which means n = 1 n = 1). EDIT: For 214 = 2 ⋅ 107 214 = 2 ⋅ 107, the other divisors are 2 2 and 107 107. Base 107 107: 214 = [2, 0] 214 = [2, 0] with sum 2 2.
Jul 14, 2014 · In general, a number is no different from an element of a group or ring. If you don't know what those are, do not worry about it. But they are just as abstract as the idea of a number. An example of a group describing something would be a knob that you turn on a fan. It might have zero, one, two, and three.
Jun 17, 2018 · Given any Integer n, the sum of the digits of n^2 is the “good number" of n. The relation is surjective (many Integers can have the same good number) For example: 2713^2 = 7360369, 7+3+6+0+3+6+9 = 34, 34 is the good number of 2713. We can recursively calculate the good number of 34,
Jan 7, 2016 · An example of an infinitesimal quantity, may be given as the ratio of the weight of an ant divided by the weight of the planet earth. For educational purposes, ratios of known things bring in implicit visualization that could lead to understanding. – NoChance. Jan 7, 2016 at 18:17. 5.
Feb 14, 2018 · What separates numbers from other mathematical objects and what justifies e.g. the quaternions to be called a number system? Can I enter China several times from Hong Kong and benefit multiple 15 day visa-free?
Dec 8, 2017 · I am currently looking at number theory and I am stuck on how exactly you work out orders of an element and non-trivial subgroups.
Mar 12, 2017 · The imaginary part of the first zero, $14.134725\ldots$, is conjectured to be a transcendental number, and it seems unlikely that there is a "nice" closed-form expression for it. $\endgroup$ – Peter Humphries
Nov 9, 2015 · For instance: 1 2 1 2 is undefinable in (R; +) (R; +). e e is undefinable in (R; +, ×) (R; +, ×). π π is (almost certainly :P) undefinable in (R; +, ×, exp) (R; +, ×, e x p). And so forth. There are even some examples which may seem to strain the limits of possibility: Fix a countable language Σ Σ, and enumerate the Σ Σ -formulas as ...
