Loci in the Argand Diagram
This Demonstration shows loci (in blue) in the Argand diagram, which should normally be recognized from their equations by high school students in certain countries. Five equations are demonstrated, each containing a constant that can be varied using the corresponding controller. The constant complex numbers and (represented by red points) are set by choosing values of , , , and .
Loci in the complex plane are usually studied by pure math students in high school in certain countries.
 B. Gaulter and M. Gaulter, Further Pure Mathematics, Oxford: Oxford University Press, 2001.