?

(FPCore (x) :precision binary64 (- (sqrt (- x 1.0)) (sqrt x)))

double code(double x) {
	return sqrt((x - 1.0)) - sqrt(x);
}

real(8) function code(x)
    real(8), intent (in) :: x
    code = sqrt((x - 1.0d0)) - sqrt(x)
end function

public static double code(double x) {
	return Math.sqrt((x - 1.0)) - Math.sqrt(x);
}

def code(x):
	return math.sqrt((x - 1.0)) - math.sqrt(x)

function code(x)
	return Float64(sqrt(Float64(x - 1.0)) - sqrt(x))
end

function tmp = code(x)
	tmp = sqrt((x - 1.0)) - sqrt(x);
end

code[x_] := N[(N[Sqrt[N[(x - 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]

\sqrt{x - 1} - \sqrt{x}