Re: HSC 2015 4U Marathon
$Let $z = x + iy,\,\,z \ne 0.\\\\\,\,\frac{1}{{x + iy}} + \frac{1}{{x - iy}} = 1\\\frac{{x - iy + x + iy}}{{\left( {x + iy} \right)\left( {x - iy} \right)}} = 1\\\\2x = {x^2} + {y^2}\\{\left( {x - 1} \right)^2} + {y^2} = 1
Circle with centre (1,0), radius 1, excluding...