Curve Defined Parametrically

The format of definition has one of the following forms:

(X(t),Y(t))

(X(t),Y(t));t_min

(X(t),Y(t));t_min,t_max

(X(t),Y(t));_,t_max

where

X(t) and Y(t) are expressions which (after evaluation) contain only variable, which is the curve’s parameter. By default variable name is t.

t_{min –}  minimal value of parameter

t_{max –}  maximal value of parameter

If neither t_min  nor t_max  are specified, the parameter varies over [0, 2π].

If t_max is not specified, the range is t > t_min ; if t_min is not specified, the range is t < t_min

Examples:
(3*cos(t),sin(t))           ; ellipse with semi-axes equal to 3 and 1

(t,t);-1,1                       ; straight segment between points (-1,-1) and (1,1)

(3*cos(17*t),3*sin(19*t))       ; Lissague curve