Question icon
Grade 11IIT JEE Entrance Exam

If all the roots of z^3+az^2+bz+c=0 are of unit modulus , then prove that mod a ≤3.

Profile image of Sumukh M Lohit
10 Years agoGrade 11
Answers icon

1 Answer

Profile image of Vijay Mukati
10 Years ago
Dear Student,
Sum of roots will be equal to -a.
Thus Modulus (alpha + beta + gamma) = a
Modulus(alpha) + Modulus(beta) + Modulus(gamma) = a
Therefore Modulas(a) = 3.