The lines Joining the origin to the points of intersection of ${\mathbf{x}}^2\mathbf{+}{\mathbf{y}}^2\mathbf{+}\mathbf{2}\mathbf{gx}\mathbf{+}\mathbf{c}\mathbf{=}\mathbf{0}$ and ${\mathbf{x}}^2\mathbf{+}{\mathbf{y}}^2\mathbf{+}\mathbf{2}\mathbf{fy}\mathbf{-}\mathbf{c}\mathbf{=}\mathbf{0}$ are perpendicular to each other then