16/04/23 19:45:23.68 5r1UlAr6.net
>>363
abb=x、bcc=y、caa=zとおくと、
(左辺)－(右辺)＝(x^3+y^3+z^3)＋3xyz－(zxx+xyy+yzz)－(zzx+xxy+yyz)
＝x(x-y)(x-z)＋y(y-z)(y-x)＋z(z-x)(z-y)
＝F_1(x y z)
≧0. (Schur)
16/04/23 19:45:23.68 5r1UlAr6.net
>>363
abb=x、bcc=y、caa=zとおくと、
(左辺)－(右辺)＝(x^3+y^3+z^3)＋3xyz－(zxx+xyy+yzz)－(zzx+xxy+yyz)
＝x(x-y)(x-z)＋y(y-z)(y-x)＋z(z-x)(z-y)
＝F_1(x y z)
≧0. (Schur)