Source: History of Mathematics (1925) Vol.2, p.461
“Cardan's originality in the matter seems to have been shown chiefly in four respects. First, he reduced the general equation to the type x^3 + bx = c; second, in a letter written August 4, 1539, he discussed the question of the irreducible case; third, he had the idea of the number of roots to be expected in the cubic; and, fourth, he made a beginning in the theory of symmetric functions. …With respect to the irreducible case… we have the cube root of a complex number, thus reaching an expression that is irreducible even though all three values of x turn out to be real. With respect to the number of roots to be expected in the cubic… before this time only two roots were ever found, negative roots being rejected. As to the question of symmetric functions, he stated that the sum of the roots is minus the coefficient of x2</sup”
Source: History of Mathematics (1925) Vol.2, pp.461-464
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David Eugene Smith 33
American mathematician 1860–1944Related quotes
Source: Mathematical Thought from Ancient to Modern Times (1972), p. 252.
Source: History of Mathematics (1925) Vol.2, p.465
However, negative numbers gained acceptance slowly.
Source: Mathematical Thought from Ancient to Modern Times (1972), p. 185.
Disme: the Art of Tenths, Or, Decimall Arithmetike (1608)
1745
Source: History of Mathematics (1925) Vol.2, p.469
Source: A Discourse of Combinations, Alterations, and Aliquot Parts (1685), Ch.II Of Alternations, or the different Change of Order, in any Number of Things proposed.
Source: Mathematical Thought from Ancient to Modern Times (1972), p. 143.
Source: History of Mathematics (1925) Vol.2, p.464