{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}\begin{array}{l}
\mathbf{if}\;n \leq -236843.41110673678:\\
\;\;\;\;\left(0.5 \cdot \frac{{\log \left(x + 1\right)}^{2}}{{n}^{2}} + \left(0.041666666666666664 \cdot \frac{{\log \left(x + 1\right)}^{4}}{{n}^{4}} + \left(\frac{\log \left(x + 1\right)}{n} + 0.16666666666666666 \cdot \frac{{\log \left(x + 1\right)}^{3}}{{n}^{3}}\right)\right)\right) - \left(\frac{\log x}{n} + \left(0.5 \cdot \frac{{\log x}^{2}}{{n}^{2}} + \left(0.041666666666666664 \cdot \frac{{\log x}^{4}}{{n}^{4}} + 0.16666666666666666 \cdot \frac{{\log x}^{3}}{{n}^{3}}\right)\right)\right)\\
\mathbf{elif}\;n \leq 1119850077.417114:\\
\;\;\;\;\sqrt[3]{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \left(\sqrt[3]{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}\right)\\
\mathbf{elif}\;n \leq 8.578898669612482 \cdot 10^{+57}:\\
\;\;\;\;\frac{\frac{e^{\frac{\log x}{n}}}{x}}{n}\\
\mathbf{else}:\\
\;\;\;\;\frac{\log \left(x + 1\right) - \log x}{n}\\
\end{array}(FPCore (x n) :precision binary64 (- (pow (+ x 1.0) (/ 1.0 n)) (pow x (/ 1.0 n))))
(FPCore (x n)
:precision binary64
(if (<= n -236843.41110673678)
(-
(+
(* 0.5 (/ (pow (log (+ x 1.0)) 2.0) (pow n 2.0)))
(+
(* 0.041666666666666664 (/ (pow (log (+ x 1.0)) 4.0) (pow n 4.0)))
(+
(/ (log (+ x 1.0)) n)
(* 0.16666666666666666 (/ (pow (log (+ x 1.0)) 3.0) (pow n 3.0))))))
(+
(/ (log x) n)
(+
(* 0.5 (/ (pow (log x) 2.0) (pow n 2.0)))
(+
(* 0.041666666666666664 (/ (pow (log x) 4.0) (pow n 4.0)))
(* 0.16666666666666666 (/ (pow (log x) 3.0) (pow n 3.0)))))))
(if (<= n 1119850077.417114)
(*
(cbrt (- (pow (+ x 1.0) (/ 1.0 n)) (pow x (/ 1.0 n))))
(*
(cbrt (- (pow (+ x 1.0) (/ 1.0 n)) (pow x (/ 1.0 n))))
(cbrt (- (pow (+ x 1.0) (/ 1.0 n)) (pow x (/ 1.0 n))))))
(if (<= n 8.578898669612482e+57)
(/ (/ (exp (/ (log x) n)) x) n)
(/ (- (log (+ x 1.0)) (log x)) n)))))double code(double x, double n) {
return pow((x + 1.0), (1.0 / n)) - pow(x, (1.0 / n));
}
double code(double x, double n) {
double tmp;
if (n <= -236843.41110673678) {
tmp = ((0.5 * (pow(log(x + 1.0), 2.0) / pow(n, 2.0))) + ((0.041666666666666664 * (pow(log(x + 1.0), 4.0) / pow(n, 4.0))) + ((log(x + 1.0) / n) + (0.16666666666666666 * (pow(log(x + 1.0), 3.0) / pow(n, 3.0)))))) - ((log(x) / n) + ((0.5 * (pow(log(x), 2.0) / pow(n, 2.0))) + ((0.041666666666666664 * (pow(log(x), 4.0) / pow(n, 4.0))) + (0.16666666666666666 * (pow(log(x), 3.0) / pow(n, 3.0))))));
} else if (n <= 1119850077.417114) {
tmp = cbrt(pow((x + 1.0), (1.0 / n)) - pow(x, (1.0 / n))) * (cbrt(pow((x + 1.0), (1.0 / n)) - pow(x, (1.0 / n))) * cbrt(pow((x + 1.0), (1.0 / n)) - pow(x, (1.0 / n))));
} else if (n <= 8.578898669612482e+57) {
tmp = (exp(log(x) / n) / x) / n;
} else {
tmp = (log(x + 1.0) - log(x)) / n;
}
return tmp;
}



Bits error versus x



Bits error versus n
Results
if n < -236843.411106736778Initial program 44.1
Taylor expanded around inf 14.0
if -236843.411106736778 < n < 1119850077.41711402Initial program 2.9
rmApplied add-cube-cbrt_binary642.9
if 1119850077.41711402 < n < 8.578898669612482e57Initial program 54.7
Taylor expanded around inf 31.4
Simplified31.4
rmApplied associate-/r*_binary6430.7
if 8.578898669612482e57 < n Initial program 42.8
Taylor expanded around inf 12.1
Simplified12.1
Final simplification11.0
herbie shell --seed 2021118
(FPCore (x n)
:name "2nthrt (problem 3.4.6)"
:precision binary64
(- (pow (+ x 1.0) (/ 1.0 n)) (pow x (/ 1.0 n))))