※ 引述《rfvbgtsport (uygh)》之銘言：
: 証明：（a的5次方）+（b的5次方）+（c的5次方）大於等於abc(ab+bc+ca)
: 謝謝
a^5+b^5+c^5
=(5a^5+5b^5+5c^5)/5
=[(2a^5+2b^5+c^5)+(a^5+2b^5+2c^5)+(2a^5+b^5+2c^5)]/5
>=[5*(a^5*a^5*b^5*b^5*c*5)^(1/5)+5*(a^5*b^5*b^5*c^5*c^5)^(1/5)
+5*(a^5*a^5*b^5*c^5*c^5)^(1/5)]/5
=a^2*b^2*c+a*b^2*c^2+a^2*b*c^2=abc(ab+bc+ca)
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