If z1,z2,z3 be three unimodular complex numbers then
E=|z1−z2|2+|z2−z3|2+|z3−z1|2 cannot exceed
A
6
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
9
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
12
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
none
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is D9 |z1−z2|2=(z1−z2)¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯(z1−z2)=(z1−z2)(¯z1−¯z2) |z1|2+|z2|2−(z1¯z2+¯z1z2) =1+1−(z1¯z2+¯¯¯¯¯¯¯¯¯¯z1¯z2)=2−2Re(z1¯z2) ∴E=(2+2+2)−2Re(z1¯z2+z2¯z3+z3¯z1) ......(1) Again |z1+z2+z3|2≥0 or 1+1+1+2Re(z1¯z2+z2¯z3+z3¯z1)≥0 or 3+(6−E)≥0 by (1)∴E≤9.