# 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: 8 Search : logarithm
 common logarithm   لگاریتم ِ دهدهی   logâritm-e dahdahiFr.: logarithme décimal   The logarithm with → base 10. It is known also as the → decimal logarithm, decadic logarithm, or Briggsian logarithm, after Henry Briggs, an English mathematician who pioneered its use.→ common; → logarithm; → decimal. decimal logarithm   لگاریتم ِ دهدهی   logâritm-e dahdahiFr.: logarithme décimal   → decimal; → logarithm. logarithm   لگاریتم   logâritm (#)Fr.: logarithme   The → exponent of the → power to which it is necessary to raise a fixed number to produce the given number. The fixed number is called the → base. The logarithm of x to the base a, denoted loga(x), is the unique → real number  y such that ay = x. In the familiar system of → common logarithms, the base is 10. In the system of → natural logarithms, the base is e = 2.7182818 ... (→ number e). For example, the logarithm of 100 (base 10) is 2 because 102 = 100.Mod.L. logarithmus, coined by Scottish mathematician John Napier (1550-1617), literally "ratio-number," from Gk. logos "proportion, ratio, word," → logic + arithmos "number," → arithmetic. logarithmic   لگاریتمی   logâritmi (#)Fr.: logarithmique   Of or pertaining to a → logarithm.→ logarithm; → -ic. logarithmic extinction   خاموشی ِ لگاریتمی   xâmuši-ye logâritmiFr.: extinction logarithmique   Same as → reddening coefficient. logarithmic scale   مرپل ِ لگاریتمی   marpel-e logâritmiFr.: échelle logarithmique   A scale of measurement in which an increase of one unit represents a tenfold increase in the quantity measured (for common logarithms)→ logarithmic; → scale. Napierian logarithm   لگاریتم ِ ناپیری   logâritm-e Napieri (#)Fr.: logarithme népérien   Same as the → natural logarithm.After John Laird Napier (1550-1617), the Scottish mathematician who invented logarithm; → logarithm. natural logarithm   لگاریتم ِ زاستاری   logâritm-e zâstâriFr.: logarithme naturel   The logarithm in which the → base is the → irrational number e = 2.718281828.... Also called → Napierian logarithm. The natural logarithm is denoted ln, an abbreviation of logarithmus naturalis. Natural logarithms are related to → common logarithms through: ln x = (1/M) log x, with M = (1/ln 10) ≅ 0.434294.→ natural; → logarithm.