Complex Numbers And Quadratic Equations question 679

Question: The locus of a point in the Argand plane that moves satisfying the equation $ |z-1+i|-|z-2-i|=3: $

Options:

A) is a circle with radius 3 and centre at $ z=\frac{3}{2} $

B) is an ellipse with its foci at $ 1-i $ and $ 2+i $ and major axis $ =3 $

C) is a hyperbola with its foci at $ 1-i $ and $ 2+i $ and its transverse axis $ =3 $

D) None of the above

Show Answer

Answer:

Correct Answer: C

Solution:

The given eq. implies that the difference between the distances of the moving point from two fixed points (1 - i) and (2 + i) is constant using the property of the hyperbola that the difference between the focal distances of any point on the curve is constant, the locus in reference is therefore a hyperbola.