type in the parametric expressions in terms of t and watch the calculator draw it! in flash player, you can use @ instead of 0 to get around a glitch. other commands: Clear Reset Redraw Set t min Set t max Set t step Set X min Set X max Set Y min Set Y max you can also use radians or degrees (click the "rad" or "deg" box) Based on Paddle2See's calculator scripts some equations to try: Circle: X = sin(t) Y = cos(t) (t is from 0 to 2*pi with step of pi/30) Tractrix: X = t-1 + 2/(e^(2*t) + 1) Y = 2/(e^t + e^-t) (t is from -4 to 4 with step 0.1)