Given ax2 + bx +c ≥0 , bx2+cx+a≥0 , cx2+ax+b≥0 where a≠b≠c and a,b,cϵR . Now a2+b2+c2ab+bc+ca cannot take the value(s)
7/9
2/7
16/3
-3/2
a>0,b>0,c>0 and
b2–4ac≤0, c2–4ab≤0 , a2–4bc≤0
⇒ a2+b2+c2 ≤4(ab+bc+ca)
And (a−b)2+(b−c)2+(c−a)2≥0
⇒1≤ a2+b2+c2ab+bc+ca ≤4