|
A Pythagorean quadruple is a tuple of integers ''a'', ''b'', ''c'' and ''d'', such that ''d > 0'' and , and is often denoted . Geometrically, a Pythagorean quadruple defines a cuboid with integer side lengths |''a''|, |''b''|, and |''c''|, whose space diagonal has integer length ''d''. Pythagorean quadruples are thus also called ''Pythagorean Boxes''.〔R.A. Beauregard and E. R. Suryanarayan, ''Pythagorean boxes'', Math. Magazine 74 (2001), 222–227.〕 == Parametrization of primitive quadruples == The set of all primitive Pythagorean quadruples, i.e., those for which gcd(''a'',''b'',''c'') = 1 where gcd denotes the greatest common divisor, and for which without loss of generality ''a'' is odd, is parametrized by,〔R.D. Carmichael, ''Diophantine Analysis'', New York: John Wiley & Sons, 1915.〕〔L.E. Dickson, ''Some relations between the theory of numbers and other branches of mathematics'', in Villat (Henri), ed., Conférence générale, Comptes rendus du Congrès international des mathématiciens, Strasbourg, Toulouse, 1921, pp. 41–56; reprint Nendeln/Liechtenstein: Kraus Reprint Limited, 1967; Collected Works 2, pp. 579–594.〕〔R. Spira, ''The diophantine equation '', Amer. Math. Monthly Vol. 69 (1962), No. 5, 360–365.〕 : : : : where ''m'', ''n'', ''p'', ''q'' are non-negative integers and gcd(''m'', ''n'', ''p'', ''q'') = 1 and ''m'' + ''n'' + ''p'' + ''q'' ≡ 1 (mod 2). Thus, all primitive Pythagorean quadruples are characterized by the Lebesgue Identity : 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Pythagorean quadruple」の詳細全文を読む スポンサード リンク
|