# The harmonic conjugate: harmonic_conjugate

### 13.17.4 The harmonic conjugate: 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.

- Input:
  harmonic_conjugate(0,2,3/2)
  Output:
- Input:
  affix(harmonic_conjugate(0,2,3/2))
  Output:

  3

- Input:
  harmonic_conjugate(line(0,1+i),line(0,3+i),line(0,i))
  Output: