AP EAMCET201922 Apr 2019Morning ShiftMathematicsComplex NumberActual
(A (z₁ ) ) and (B (z₂ ) ) are two points in the argand plane. Then, the locus of the complex number (z ) satisfying ( ( z-z₁ z-z₂ )=0 ) or ( ), is
Options
- Athe circle with ( A B ) as a diameter
- Bthe ellipse with (A, B ) as extremities of the major axis
- Cthe perpendicular bisector of ( A B )
- Dthe straight line passing through the points (A ) and (B )
Correct answer
D. the straight line passing through the points (A ) and (B )
Step-by-step solution
Let the point (z(x, y), z₁ (x₁, y₁ ) ) and (z₂ (x₂, y₂ ) ). ( aligned & z-z₁=x+i y-x₁-i y₁ & =x-x₁+i (y-y₁ ) & and z-z₂=x+i y-x₂-i y₂ & =x-x₂+i (y-y₂ ) aligned ) Now, ( z-z₁ z-z₂ ) ( aligned & = [ (x-x₁ )+i (y-y₁ ) ] [ (x-x₂ )+i (y-y₂ ) ] [ (x-x₂ )-i (y-y₂ ) ] [ (x-x₂ )-i (y-y₂ ) ] & (x-x₁ ) (x-x₂ )+ (y-y₁ ) (y-y₂ )+ & = i [ (x-x₂ ) (y-y₁ )- (x-x₁ ) (y-y₂ ) ] (x-x₂ )^2+ (y-y₂ )^2 & = Arg ( z-z₁ z-z₂ )=0 or & [ [ (x-x₂ ) (y-y₁ ) ]- [ (x-x₁ ) (y-y₂ ) ] [ (x-x₁ ) (x-x₂ )+ (y-y₁ ) (y-y₂ ) ] ]=0 & (x-x₂ ) (y-y₁ )= (x-x₁