No valid values. (more)

\[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}
double code(double x) {
	return ((double) sqrt(((double) (((double) (((double) exp(((double) (2.0 * x)))) - 1.0)) / ((double) (((double) exp(x)) - 1.0))))));
}

Reproduce

herbie shell --seed 2020156 
(FPCore (x)
  :name "sqrtexp (problem 3.4.4)"
  :precision binary64
  (sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))