Returns the non-negative square root of the argument.
math:sqrt( $arg as xs:double?xs:double?If $arg is the empty sequence, the function returns the empty sequence.
Otherwise the result is the mathematical non-negative square root of $arg
as defined in the specification of the
squareRoot function applied to 64-bit binary floating point values.
The expression math:sqrt(()) returns ().
The expression math:sqrt(0.0e0) returns 0.0e0.
The expression math:sqrt(-0.0e0) returns -0.0e0.
The expression math:sqrt(1.0e6) returns 1.0e3.
The expression math:sqrt(2.0e0) returns 1.4142135623730951e0.
The expression math:sqrt(-2.0e0) returns xs:double('NaN').
The expression math:sqrt(xs:double('NaN')) returns xs:double('NaN').
The expression math:sqrt(xs:double('INF')) returns xs:double('INF').
The expression math:sqrt(xs:double('-INF')) returns xs:double('NaN').
The treatment of the invalidOperation exception is defined in . The effect is that if the argument is less than zero, the result
is NaN.
If $arg is positive or negative zero, positive infinity, or
NaN, then the result is $arg. (Negative zero is the only
case where the result can have negative sign)