■ヨハン・アルブレヒト・オイラーの不等式(その41)
2乗すると
36(x^2+y^2+z^2+w^2)^2
=(x−y)^4+(z−w)^4+(x+y)^4+(z+w)^4
+(x−z)^4+(y−w)^4+(x+z)^4+(y+w)^4
+(x−w)^4+(y−z)^4+(x+w)^4+(y+z)^4
+2{(x−y)^2(x+y)^2+(z−w)^2(z+w)^2}
+2{(x−z)^2(x+z)^2+(y−w)^2(y+w)^2}
+2{(x−w)^2(x+w)^2+(y−z)^2(y+z)^2}
+2・・・
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[雑感]x^6+y^6+z^6+u^6+v^6+w^6−6xyzuvw
=(x^2+y^2+z^2)/2・{(y^2−z^2)^2+(z^2−x^2)^2+(x^2−y^2)^2}+(u^2+v^2+w^2)/2・{(v^2−w^2)^2+(w^2−u^2)^2+(u^2−v^2)^2}+3(xyz−uvw)^2
F=x^6+y^6+z^6+u^6+v^6+w^6
=(x^2+y^2+z^2)/2・{(y^2−z^2)^2+(z^2−x^2)^2+(x^2−y^2)^2}+(u^2+v^2+w^2)/2・{(v^2−w^2)^2+(w^2−u^2)^2+(u^2−v^2)^2}+3(xyz)^2+3(uvw)^2
についても,同様の変形が可能だろうか?
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