cho a+b+c=0 cm
a a^4+b^4+c^4=2(a^2.b^2+b^2.c^2+c^2.a^2)
Cho a+b+c=0, cm a)a^3+b^3+c^3=3abc
b) a^2+b^2+c^2=2(a^4+b^4+c^4)
Cho a+b+c=0
CM: (a^2+b^2+c^2)^2=2(a^4+b^4+c^4)
cho a+b+c=0 CM a^4 +b^4+c^4=
2(a^2*b^2+b^2*c^2+c^2*a^2)
2(ab+bc+ca)^2
(a^2+b^2+c^2)^2 \ 2
cho a+b+c=0. CM: a^4 +b^4 +c^4 = (a2 + b2 + c2)2 :2
Cho a+b+c=0.Cm đẳng thức:
a) \(a^4+b^4+c^4=2\left(ab+bc+ac\right)^2\)
b) \(a^4+b^4+c^4=\frac{\left(a^2+b^2+c^2\right)^2}{2}\)
Cho a+b+c=0. Cm a4 +b4 +c4 =1/2(a2 +b2 +c2 )2
Cho a,b,c>0. CM: \(\frac{a^4+b^4+c^4}{ab+bc+ca}+\frac{3abc}{a+b+c}\ge\frac{2}{3}.\left(a^2+b^2+c^2\right)\)
Cho a+b+c=0
cm a4+b4+c4=1/2(a2+b2+c2)2
