If z1=z3=z3=1 then value of z2−z32+z3−z12+z1−z22 cannot exceed

z1+z2+z3≥0⇒z12+z22+z32+2Re⁡z1z¯2+z2z¯3+z3z¯1≥0⇒Re⁡z1z¯2+z2z¯3+z3z¯1≥−32Now, z2−z32+z3−z12+z1−z22=6−2Re⁡z1z¯2+z2z¯3+z3z¯1≤6−(−3)=9