### 26.16.4 Harmonic conjugate

The harmonic_conjugate command finds harmonic conjugates.

- harmonic_conjugate takes three arguments: P1,P2,P3, three collinear points or three concurrent lines, or three parallel lines.
- harmonic_conjugate(P1,P2,P3) returns and draws the harmonic conjugate of P1,P2 and P3.

#### Examples

A,B,C:=point(i),point(2+i),point(1/3+i); D:=harmonic_conjugate(A,B,C)

evalc(affix(D))

−

1
2

+i

harmonic_conjugate(line(0,1+i),line(0,3+i),line(0,i))