JEE Advanced2025MathematicsComplex NumberActual
Let R denote the set of all real numbers. Let z₁=1+2 i and z₂=3 i be two complex numbers, where i= -1 . Let S= (x, y) R R : |x+i y-z₁ |=2 |x+i y-z₂ | . Then which of the following statements is (are) TRUE?
Options
- AS is a circle with centre (- 1 3 , 10 3 )
- BS is a circle with centre ( 1 3 , 8 3 )
- CS is a circle with radius 2 3
- DS is a circle with radius 2 2 3
Correct answer
A. S is a circle with centre (- 1 3 , 10 3 )
Step-by-step solution
aligned & aligned & |x+i y-1-2 i|=2|x+i y-3 i| & (x-1)^2+(y-2)^2=4 (x^2+(y-3)^2 ) & 3 x^2+3 y^2+2 x-20 y+31=0 & x^2+y^2+ 2 x 3 - 20 y 3 + 31 3 =0 aligned & S is a circle with centre (- 1 3 , 10 3 ) and radius = 1 9 + 100 9 - 31 3 = 8 9 = 2 2 3 aligned