Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Advanced2021MathematicsComplex NumberActual

For any complex number w = c + i d , let arg w ∈ ( - π , π ] , where i = - 1 . Let α and β be real numbers such that for all complex numbers z = x + i y satisfying arg z + α z + β = π 4 , the ordered pair ( x , y ) lies on the circle x 2 + y 2 + 5 x - 3 y + 4 = 0 Then which of the following statements is(are) TRUE?

Options

  1. Aα = - 1
  2. Bα β = 4
  3. Cα β = - 4
  4. Dβ = 4

Correct answer

B. α β = 4

Step-by-step solution

arg z + α z + β = π 4 represents an arc of a circle and - α , 0   &   - β , 0 subtends an angle π 4 on z Given, x 2 + y 2 + 5 x - 3 y + 4 = 0 Centre - 5 2 , 3 2 ,   r = 25 4 + 9 4 - 4 = 3 2 Angle made by ( - α , 0 )   &   ( - β , 0 ) at the centre C is π 2 Using rotation of complex numbers, we get - α - - 5 2 + 3 2 i - β - - 5 2 + 3 2 i = 1 · e i π 2 = i - α + 5 2 - 3 2 i = - i β + 5 2 i + 3 2 α - i &#94

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 Advanced PYQs