### 11.13.8 The parametric equation of a geometric object in the plane: parameq

See section 12.12.6 for parametric equations in three-dimensional geometry.

The parameq command takes as argument a geometric object.

parameq returns a parametric equation of the object, in the form x(t) + i*y(t). (Note that t must be a formal variable, it may be necessary to purge it with purge(t).)
Input:

parameq(line(-1,i))

Output:

t + (1-t)*i

Input:

parameq(circle(-1,i))

Output:

-1 + exp(i*t)

Input:

normal(parameq(ellipse(-1,1,i)))

Output:

sqrt(2)*cos(t) + i*sin(t)