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tan(+Number, -Result)

-Result is tan(+Number)

Evaluates the trigonometric function tan(Number) and unifies the resulting value with Result.
Number
A number.
Result
Output: float or breal.

Description

Evaluates the trigonometric function tan(Number) and unifies the resulting value with Result.

This predicate can be used as a function in arithmetic expressions. In coroutining mode, if Number is uninstantiated, the call to tan/2 is delayed until this variable is instantiated.

Modes and Determinism

Exceptions

(4) instantiation fault
Number is not instantiated (non-coroutining mode only).
(24) number expected
Number is not of a numeric type.
(20) arithmetic exception
Illegal arithmetic operation: Number is (2k +1) * pi/2 for every integer k.

Examples

Success:
    Result is tan(0).		% gives Result = 0.0
    Result is tan(12.3).        % gives Result = -0.272854
    Result is tan(-1).          % gives Result = -1.55741

Error:
    X is pi/2, tan(X). 		% arithmetic exception

See Also

is / 2