\frac{x - \sin x}{x - \tan x}\begin{array}{l}
\mathbf{if}\;x \le -0.029152232486199241 \lor \neg \left(x \le 0.0281843105629446845\right):\\
\;\;\;\;\frac{{\left(\frac{x}{x - \tan x}\right)}^{3} - {\left(\frac{\sin x}{x - \tan x}\right)}^{3}}{\frac{x}{x - \tan x} \cdot \frac{x}{x - \tan x} + \frac{\sin x}{x - \tan x} \cdot \left(\frac{x}{x - \tan x} + \frac{\sin x}{x - \tan x}\right)}\\
\mathbf{else}:\\
\;\;\;\;\left(\frac{9}{40} \cdot {x}^{2} - \frac{27}{2800} \cdot {x}^{4}\right) - \frac{1}{2}\\
\end{array}double f(double x) {
double r21580 = x;
double r21581 = sin(r21580);
double r21582 = r21580 - r21581;
double r21583 = tan(r21580);
double r21584 = r21580 - r21583;
double r21585 = r21582 / r21584;
return r21585;
}
double f(double x) {
double r21586 = x;
double r21587 = -0.02915223248619924;
bool r21588 = r21586 <= r21587;
double r21589 = 0.028184310562944685;
bool r21590 = r21586 <= r21589;
double r21591 = !r21590;
bool r21592 = r21588 || r21591;
double r21593 = tan(r21586);
double r21594 = r21586 - r21593;
double r21595 = r21586 / r21594;
double r21596 = 3.0;
double r21597 = pow(r21595, r21596);
double r21598 = sin(r21586);
double r21599 = r21598 / r21594;
double r21600 = pow(r21599, r21596);
double r21601 = r21597 - r21600;
double r21602 = r21595 * r21595;
double r21603 = r21595 + r21599;
double r21604 = r21599 * r21603;
double r21605 = r21602 + r21604;
double r21606 = r21601 / r21605;
double r21607 = 0.225;
double r21608 = 2.0;
double r21609 = pow(r21586, r21608);
double r21610 = r21607 * r21609;
double r21611 = 0.009642857142857142;
double r21612 = 4.0;
double r21613 = pow(r21586, r21612);
double r21614 = r21611 * r21613;
double r21615 = r21610 - r21614;
double r21616 = 0.5;
double r21617 = r21615 - r21616;
double r21618 = r21592 ? r21606 : r21617;
return r21618;
}



Bits error versus x
Results
if x < -0.02915223248619924 or 0.028184310562944685 < x Initial program 0.0
rmApplied div-sub0.0
rmApplied flip3--0.1
Simplified0.1
if -0.02915223248619924 < x < 0.028184310562944685Initial program 63.2
Taylor expanded around 0 0.0
rmApplied associate--r+0.0
Final simplification0.0
herbie shell --seed 2019198
(FPCore (x)
:name "sintan (problem 3.4.5)"
(/ (- x (sin x)) (- x (tan x))))