0359132人目の素数さん垢版 | 大砲2018/11/19(月) 23:43:46.25ID:eL1RQpps >>350 >>353 (a^2 -b)(c^2 -d) = (7/6 -f/2)^2 - (20/27)^2/(7/6 +f/2) = (1/3) [(13+2√11)^{1/3} - (13-2√11)^{1/3}]^2 = -0.237618966426144 < 0,