
Complex Numbers  Argand Diagram Question
Posted:
Sep 26, 2011 8:27 PM


Complex Numbers  Argand Diagram Question
In Gow's book, A Course in Pure Mathematics, I have managed to answer all of the complex number questions in Chapter 6 except question 21.
21. If the complex numbers z_1, z_2, z_3 are connected by the relation
2/z_1 = 1/z_2 + 1/z_3
show that the points Z1, Z2, Z3 representing them in an Argand diagram lie on a circle passing through the origin.
Note: _1, _2, _3 denote subscripts.
I have tried algebraic and geometrical approaches. One attempt was to show that the three points, along with the origin, form a cyclic quadrilateral.
I used a CAS to draw a diagram for the problem, but after many hours I don't seem to be any closer to finding a solution.
Any help much appreciated.
Cheers, Brad

