### 26.16.5 Pole and polar

Given a circle centered at O, a point A is a pole and a line L is the corresponding polar if L is the line passing through the inversion of A with respect to the circle (see Section 26.14.7) passing through the line OA.

The polar command finds the polar of a point.

- polar takes two arguments:
  - C, a circle.
  - A, a point.
- polar(C,A) returns and draws the polar of the point A with respect to C.

#### Example

C:=circle(0,1); A:=point((i+1)/2); L:=polar(C,A)

The pole command finds the pole of a line.

- pole takes two arguments:
  - C, a circle.
  - L, a line
- pole(C,L) returns and draws the pole of the line L with respect to C.

#### Examples

C:=circle(0,1); L:=line(i,1); P:=pole(C,L)

affix(P)

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