19/03/20 00:24:16.95 CRVJH54b.net
(x^3 -x +1) = (x-a)(x^2 +ax +b)
ここに
a = －{(9-√69)/18}^(1/3) －{(9+√69)/18}^(1/3) = -1.324717957
b = -1/a = (1/3)[ {(25-3√69)/2}^(1/3) + {(25+3√69)/2}^(1/3) - 1] = 0.754877666
だね
19/03/20 00:24:16.95 CRVJH54b.net
(x^3 -x +1) = (x-a)(x^2 +ax +b)
ここに
a = －{(9-√69)/18}^(1/3) －{(9+√69)/18}^(1/3) = -1.324717957
b = -1/a = (1/3)[ {(25-3√69)/2}^(1/3) + {(25+3√69)/2}^(1/3) - 1] = 0.754877666
だね