# a+certain+number+of

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**Got to Be Certain**— Infobox Single Name = Got to Be Certain Artist = Kylie Minogue from Album = Kylie B side = Released = Start date|1988|5|2 Format = CD single, 12 inch single, 7 inch single, Cassette single Recorded = Genre = Dance pop Length = 3:17 Label = PWL,… …52

**Irrational number**— In mathematics, an irrational number is any real number that is not a rational number that is, it is a number which cannot be expressed as a fraction m / n , where m and n are integers, with n non zero. Informally, this means numbers that cannot… …53

**Complex number**— A complex number can be visually represented as a pair of numbers forming a vector on a diagram called an Argand diagram, representing the complex plane. Re is the real axis, Im is the imaginary axis, and i is the square root of –1. A complex… …54

**F-number**— In optics, the f number (sometimes called focal ratio, f ratio, or relative aperture [Smith, Warren Modern Lens Design 2005 McGraw Hill] ) of an optical system expresses the diameter of the entrance pupil in terms of the focal length of the lens; …55

**Random number generation**— A random number generator (often abbreviated as RNG) is a computational or physical device designed to generate a sequence of numbers or symbols that lack any pattern, i.e. appear random. Computer based systems for random number generation are… …56

**General number field sieve**— In number theory, the general number field sieve (GNFS) is the most efficient classical algorithm known for factoring integers larger than 100 digits. Heuristically, its complexity for factoring an integer n (consisting of log2 n bits) is of …57

**Graham's number**— Graham s number, named after Ronald Graham, is a large number that is an upper bound on the solution to a certain problem in Ramsey theory. This number gained a degree of popular attention when Martin Gardner described it in the Mathematical… …58

**Real number**— For the real numbers used in descriptive set theory, see Baire space (set theory). For the computing datatype, see Floating point number. A symbol of the set of real numbers …59

**Ordinal number**— This article is about the mathematical concept. For number words denoting a position in a sequence ( first , second , third , etc.), see Ordinal number (linguistics). Representation of the ordinal numbers up to ωω. Each turn of the spiral… …60

**Magic number**— ██████████ …