Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE MainMathematicsComplex Number

Let z₁ and z₂ be the roots of the equation z^4 + 16 = 0 that lie in the upper half of the complex plane. Let L be the line passing through z₁ and z₂ . If L divides the circular region |z| 2 into two parts of areas and ( > ), then the value of - is :

Options

  1. A2
  2. B2 + 4
  3. C3 + 2
  4. D2 + 2

Correct answer

B. 2 + 4

Step-by-step solution

The roots of z^4 + 16 = 0 are given by z = (-16)^ 1/4 = (16 e^ i )^ 1/4 . z = 2 e^ i( + 2k )/4 for k = 0, 1, 2, 3 . For k = 0 , z₁ = 2 e^ i /4 = 2 + i 2 . For k = 1 , z₂ = 2 e^ i3 /4 = - 2 + i 2 . For k = 2 , z₃ = 2 e^ i5 /4 = - 2 - i 2 . For k = 3 , z₄ = 2 e^ i7 /4 = 2 - i 2 . The roots in the upper half plane (where the imaginary part is positive) are z₁ and z₂ . The line L passing through z₁ and z₂ is horizontal, with equation y = 2 . The region |z| 2 represents a circle centered at the origin (0,0) with radius

Practice Complex Number on Quantrex Academy →

More from Complex Number

The number of values of z C , satisfying the equations |z-(4+8i)|= 10 and |z-(3+5i)|+|z-(5+11i)|=4 5 , is: 2026Let S = z C : z^2 + 6 ,iz - 3 = 0 . Then _ z S z^8 is equal to : 2026Let the set of all values of k R such that the equation z( z + 2 + i) + k(2 + 3i) = 0 , z C , has at least one solution, be the interval [ , ] . Then 9( + ) is equal to: 2026Let z₁, z₂ C be the distinct solutions of the equation z^2 + 4z - (1 + 12i) = 0 . Then |z₁|^2 + |z₂|^2 is equal to : 2026Let S= z C : z^2+4z+16=0 . Then _ z S |z+ 3 i|^2 is equal to: 2026Let z be a complex number such that |z+2| = |z-2| and ( z+3 z-i ) = 4 . Then |z|^2 is equal to: 2026Let the circles C₁ : |z| = r and C₂ : |z - 3 - 4i| = 5 , z C , be such that C₂ lies within C₁ . If z₁ moves on C₁ , z₂ moves on C₂ and |z₁ - z₂| = 2 , then |z₁ - z₂| is equal to: 2026Let x and y be real numbers such that 50 ( 2x 1+3i - y 1-2i ) = 31 + 17i , i = -1 . Then the value of 10(x - 3y) is : 2026 Full Complex Number list All JEE Main PYQs