# math:asin - XPath XQuery Reference

Returns the arc sine of the argument.deterministiccontext-independentfocus-independentIf $arg is the empty sequence, the function returns the empty sequence.Otherwise the result is the arc sine of $arg as defined in the  specification of the
            asin function applied to 64-bit binary floating point values. 
            The result is in the range -π/2 to +π/2 radians. math:asin(())()math:asin(0)0.0e0math:asin(-0.0e0)-0.0e0math:asin(1.0e0)1.5707963267948966e0math:asin(-1.0e0)-1.5707963267948966e0math:asin(2.0e0)xs:double('NaN')math:asin(xs:double('NaN'))xs:double('NaN')math:asin(xs:double('INF'))xs:double('NaN')math:asin(xs:double('-INF'))xs:double('NaN')The treatment of the invalidOperation and underflow exceptions
            is defined in . If $arg is positive or negative zero, the result is $arg.If $arg is NaN, or if its absolute value is greater than one,
            then the result is NaN.In other cases the result is an xs:double value representing an angle
               θ in radians in the range -π/2 <=
               θ <= +π/2.