Returns the correctly rounded positive square root of a
double
value.
Special cases:
- If the argument is NaN or less than zero, then the result
is NaN.
- If the argument is positive infinity, then the result is positive
infinity.
- If the argument is positive zero or negative zero, then the
result is the same as the argument.
Otherwise, the result is the
double
value closest to
the true mathematical square root of the argument value.
Parameters:
Returns: the positive square root of a
.