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Tag - Numbers

Infinite Number of Primes Sat, Jul 22, 2017 02:00 CEST

The erroneous proof I hear most often is: Suppose $$P$$ is a finite set that contains all the primes, then $$p^* = 1 + \prod_{p \in P} p$$ is prime. Indeed, the flaw is that $$p^*$$ is not necessarily prime but rather must be a multiple of some prime not in $$P$$.

Symbols Sun, Nov 8, 2015 01:00 CET

$$\mathbb{N} \subset \mathbb{Z} \subset \mathbb{Q} \subset \mathbb{R} \subset \mathbb{C}$$

Fibonacci numbers Mon, Jun 29, 2015 02:00 CEST

The Fibonacci numbers are defined as $$f_0 = 0,\ f_1 = 1$$ and, for $$i \ge 2,\ f_i = f_{i-1} + f_{i-2}$$. Here is the beginning of the Fibonacci sequence:

$$0, 1, 1, 2, 3, 5, 8, 13, 21, \ldots$$

We generalize the definition above by changing the two initial values, for example with $$f_0 = 4,\ f_1 = 6$$ we obtain

$$4, 6, 10, 16, 26, 42, \ldots$$

Complex numbers division Tue, Jun 23, 2015 02:00 CEST

$$\frac{a+bi}{c+di} = \ldots$$