### 19.7.1 2D parametric curve

- To draw a parametric curve in ℝ2, plotparam takes two mandatory and one optional argument:
  - exprs, a list of two real expressions or one complex expression involving the parameter.
  - var, the parameter, optionally with a range var=a..b. If no range is given, the values of t- and t+ from the graphics configuration will be used (see Section 2.5.8).
  - Optionally, tstep=n, to set the discretization step.
- plotparam(exprs,var ⟨,tstep=n ⟩) draws the parametric representation of the curve.

#### Examples

plotparam(cos(x)+i*sin(x),x)

or:

plotparam([cos(x),sin(x)],x)

plotparam(sin(t)+i*cos(t),t=-4..1)

or:

plotparam(sin(x)+i*cos(x),x=-4..1)

or, with t-=4,t+=1 in the graphic configuration:

plotparam(sin(t)+i*cos(t))

plotparam(sin(t)+i*cos(t),t=-4..1,tstep=0.5)

or, with t-=4,t+=1 in the graphic configuration:

plotparam(sin(t)+i*cos(t),t,tstep=0.5)