#### 8.1.15 Polar

• Polar( <r(t)> [, n, 0/1] ) or Polaire( <r(t)> [, n, 0/1] ).
• Description: draw the polar curve of equation $\rho =r\left(t\right)$.The optional parameter <n> is an integer (5 by default) that permit to vary the step in the following way: when the distance between two consecutive points is greater than a limit, then an intermediate point is calculated (using dichotomy), this can be repeated $n$ times. If after $n$ iterations the distance between two points is still greater than the limit, and if the optional value $1$ is present, then a discontinuity (jump) is inserted in the point list.

 \begin{texgraph}[name=Polaire,export=pgf]   view(-3,2,-2,3),Marges(0.25,0.25,0.25,0.25),   size(7.5),Width:=4,   Axes(0,1+i),NbPoints:=250,tMin:=-25,tMax:=25,   courbe:=Get(Polaire((t+1)/(t-1))),   ptDoubles:= courbe InterL courbe,   Width:=8, Color:= blue, Ligne(courbe,0),   DotStyle:=dotcircle, DotScale:=2,   Point(ptDoubles),   Label(1+2*i,"$r(t)=\dfrac{t+1}{t-1}$")   \end{texgraph}

Polar curve and double point