Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
KVPY2015MathematicsComplex Number

If z is a complex number satisfying |z³+z⁻³ | 2 , then the maximum possible value of |z+z⁻¹ | is

Options

  1. A2
  2. B[3] 2
  3. C2 2
  4. D1

Correct answer

A. 2

Step-by-step solution

|z³+ 1 z³ | 2 But we know that |z³+ 1 z³ | |z|³+ 1 |z|³ So when | z |=1 by AM GM | z |³+ 1 | z |³ =2 Now | z + 1 z | | z |+ 1 | z | =2 Maximum value =2

Practice Complex Number on Quantrex Academy →

More from Complex Number

If z and are two non-zero complex numbers such that |z |=1 and Arg z- Arg = 2 then z = 2025Let z satisfy |z|=1, z=1- z and Im (z)>0 Statement-I : z is a real number Statement-II : Principal argument of z is 3 . Then 2025If ₁ and ₂ are two non-zero complex numbers and a , b are non zero real numbers such that | a ₁+ b ₂ |= | a ₁- b ₂ | , then ₁ ₂ is 2025If a complex number z=x+i y represents a point P on the Argand plane and Arg ( z-3+2 i z+2-3 i )= 4 , then the locus of P is a 2025By taking a i b =x i y, x>0 , if we get 21+12 2 i 21-12 2 i =a+i b , then b a = 2025Two values of (-8-8 3 i)^ 1 / 4 are 2025If x=3-2 3 i , then x^4-12 x^3+54 x^2-108 x-54= 2025z ₁, z ₂, z ₃ represent the vertices A , B , C of a triangle ABC respectively in the Argand plane. If |z₁-z₂ |= 25-12 3 , | z₁-z₃ z₂-z₃ |= 3 4 and ACB =30^ , then the area (in sq. 2025 Full Complex Number list All KVPY PYQs