Returns the cosine of the argument. The argument is an angle in radians.
math:cos( $θ as xs:double?xs:double?If $
θ is the empty sequence, the function returns the empty
sequence.
If $
θ is positive or negative infinity, or NaN,
then the result is NaN.
Otherwise the result is the cosine of $
θ (which is treated as an angle in
radians) as defined in the specification of the
cos function applied to 64-bit binary floating point values.
The expression math:cos(()) returns ().
The expression math:cos(0) returns 1.0e0.
The expression math:cos(-0.0e0) returns 1.0e0.
The expression math:cos(math:pi() div 2) returns 0.0e0.
The expression math:cos(-math:pi() div 2) returns 0.0e0.
The expression math:cos(math:pi()) returns -1.0e0.
The expression math:cos(xs:double('NaN')) returns xs:double('NaN').
The expression math:cos(xs:double('INF')) returns xs:double('NaN').
The expression math:cos(xs:double('-INF')) returns xs:double('NaN').
The treatment of the invalidOperation exception is defined in .
If $
θ is positive or negative zero, the result is
$
θ.
If $
θ is positive or negative infinity, or NaN,
then the result is NaN.
Otherwise the result is always in the range -1.0e0 to +1.0e0