\log \left(N + 1\right) - \log N
\begin{array}{l}
\mathbf{if}\;N \le 6381.7936198495444841682910919189453125:\\
\;\;\;\;\frac{1}{2} \cdot \log \left(\frac{N + 1}{N}\right) + \left(\log \left(\sqrt{\frac{\sqrt{N + 1}}{1}}\right) + \log \left(\sqrt{\frac{\sqrt{N + 1}}{N}}\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{{N}^{2}} \cdot \left(\frac{0.3333333333333333148296162562473909929395}{N} - 0.5\right) + \frac{1}{N}\\
\end{array}double f(double N) {
double r41397 = N;
double r41398 = 1.0;
double r41399 = r41397 + r41398;
double r41400 = log(r41399);
double r41401 = log(r41397);
double r41402 = r41400 - r41401;
return r41402;
}
double f(double N) {
double r41403 = N;
double r41404 = 6381.7936198495445;
bool r41405 = r41403 <= r41404;
double r41406 = 0.5;
double r41407 = 1.0;
double r41408 = r41403 + r41407;
double r41409 = r41408 / r41403;
double r41410 = log(r41409);
double r41411 = r41406 * r41410;
double r41412 = sqrt(r41408);
double r41413 = 1.0;
double r41414 = r41412 / r41413;
double r41415 = sqrt(r41414);
double r41416 = log(r41415);
double r41417 = r41412 / r41403;
double r41418 = sqrt(r41417);
double r41419 = log(r41418);
double r41420 = r41416 + r41419;
double r41421 = r41411 + r41420;
double r41422 = 2.0;
double r41423 = pow(r41403, r41422);
double r41424 = r41413 / r41423;
double r41425 = 0.3333333333333333;
double r41426 = r41425 / r41403;
double r41427 = 0.5;
double r41428 = r41426 - r41427;
double r41429 = r41424 * r41428;
double r41430 = r41407 / r41403;
double r41431 = r41429 + r41430;
double r41432 = r41405 ? r41421 : r41431;
return r41432;
}



Bits error versus N
Results
if N < 6381.7936198495445Initial program 0.1
rmApplied diff-log0.1
rmApplied add-sqr-sqrt0.1
Applied log-prod0.1
rmApplied pow1/20.1
Applied log-pow0.1
rmApplied *-un-lft-identity0.1
Applied add-sqr-sqrt0.1
Applied times-frac0.1
Applied sqrt-prod0.1
Applied log-prod0.1
if 6381.7936198495445 < N Initial program 59.4
Taylor expanded around inf 0.0
Simplified0.0
Final simplification0.1
herbie shell --seed 2020001
(FPCore (N)
:name "2log (problem 3.3.6)"
:precision binary64
(- (log (+ N 1)) (log N)))