Let a,b,c be non-zero real numbers such that a+b+c = 0; let q=a2+b2+c2 and r=a4+b4+c4 Then
q2 < 2r always
q2 = 2r always
q2 > 2r always
q2 - 2r can take both positive and negative value
a+b+c=0,a,b,c ϵR≠0a2+b2+c2+2(ab+bc+ca)=0q=a2+b2+c2,r=a4+b4+c4r=q2−2(a2b2+b2c2+c2a2)r=q2−2[(ab+bc+ca)2−2abc(a+b+c)]r=q2−2(q2/4)r=q2/2