An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 4 Search : progression
 arithmetic progression   فرایازی ِ حسابی   farâyâzi-yz hesâbi (#)Fr.: progression arithmétique   A → sequence of n numbers or quantities such that the difference between any two successive terms is a constant. In particular, if a is the first term, the nth term is a + (n - 1)d, where d is the constant. Also called → arithmetic sequence. geometric progression   فرایازی ِ هندسی   farâyâsi-e hendesi (#)Fr.: progression géométrique   A → sequence in which the ratio of a term to its predecessor is the same for all terms. In general, the nth term has the form ar(n-1), where n is a positive integer, and a and r are nonzero constants; r is called the ratio or common ratio. The sum of the first n terms is given by: Sn = a(1 - rn)/(1 - r). Also called → geometric sequence.→ geometric; → progression. harmonic progression   فرایازی ِ هماهنگ   farâyâzi-ye hamâhangFr.: progression harmonique   Math.: Any ordered set of numbers, the reciprocals of which have a constant difference between them. For example 1, ½, 1/3, ¼, ..., 1/n. Also called → harmonic sequence. progression   فرایازی   farâyâzi (#)Fr.: progression   Math.: A succession of numbers or quantities in which there is a constant relation between each member and the one succeeding it. See also → arithmetic progression, → geometric progression, → harmonic progression.From O.Fr. progression, from L. progressionem "a going forward," from progressus, p.p. of progredi "go forward," from → pro- "forward" + gradi "to step, walk," from gradus "step."Farâyâzi, from farâ-, → pro-, + yâzi, verbal noun of yâzidan "to stretch out the arms; grow up;" Parthian Mid.Pers. y'd "to reach a goal, come to, stretch out;" Av. yat- to reach, take one's place," yaiiata "places,' frā-iiatāt "has reached;" cf. Skt. yat- "to be in place, put in place, line up;" PIE base *iet- "to be in place."