13.17.2 The cross ratio of four collinear points: cross_ratio
The cross ratio of four numbers a,b,c,d is
[(c−a)/(c−b)]/[(d−a)/(d−b)].
The cross_ratio command finds the cross ratio.
-
cross_ratio takes for arguments:
a,b,c,d, complex numbers.
- cross_ratio(a,b,c,d) returns the cross ratio,
[(c−a)/(c−b)]/[(d−a)/(d−b)].
Examples.