SymPy Gamma

SymPy:

plot (x =cos (t),y =sin (t))

$\mathrm{Plot~}\left\{ x : \cos{\left(t \right)}, \ y : \sin{\left(t \right)}\right\}$

Plot:

plot(p1=(cos(t), sin(t)))

See what Wolfram|Alpha has to say.

Experiment with SymPy at SymPy Live.