If you click  here  and  here   you can see the graphs.

You can have these files used by directing students to:
or you can save them (with extension ".php", possibly changing the names) in any computer.
The curves are:   x=(cos(t)-(sin(t)^2)/sqrt(2)), y=sin(t)*cos(t);   x=cos(t)^3, y=sin(t)^3.

See this document for other "php" charts, for more information on them, and to see how to change them.