This arithmetic predicate calculates the arc cosines of the argument. This predicate is not in the ISO Prolog standard.
see also: atan/1 arithmetic in Prolog cos/1 cosh/1 is/2 sin/1 sinh/1 tan/1 tanh/1
| Examples | |
| X is acos(1.1). | a domain_error(value, acos(1.1)) exception is thrown |
| X is acos(-0.1). | succeeds, X is 1.670964 |
| Exceptions | |
| Number is smaller than -1.0 or larger than +1.0 | a domain_error(value, A) exception is thrown, A is replaced by the expression that causes the overflow, for example: acos(1.1) |
| The result exceeds the floating point range | an evaluation_error(float_overflow) exception is thrown |