\frac{x - \sin x}{x - \tan x}\begin{array}{l}
\mathbf{if}\;x \le -0.0290170878265866537 \lor \neg \left(x \le 0.0311971006789354723\right):\\
\;\;\;\;\frac{x}{x - \tan x} - \frac{\sin x}{x - \tan x}\\
\mathbf{else}:\\
\;\;\;\;\frac{9}{40} \cdot {x}^{2} - \left(\frac{27}{2800} \cdot {x}^{4} + \frac{1}{2}\right)\\
\end{array}double f(double x) {
double r11280 = x;
double r11281 = sin(r11280);
double r11282 = r11280 - r11281;
double r11283 = tan(r11280);
double r11284 = r11280 - r11283;
double r11285 = r11282 / r11284;
return r11285;
}
double f(double x) {
double r11286 = x;
double r11287 = -0.029017087826586654;
bool r11288 = r11286 <= r11287;
double r11289 = 0.031197100678935472;
bool r11290 = r11286 <= r11289;
double r11291 = !r11290;
bool r11292 = r11288 || r11291;
double r11293 = tan(r11286);
double r11294 = r11286 - r11293;
double r11295 = r11286 / r11294;
double r11296 = sin(r11286);
double r11297 = r11296 / r11294;
double r11298 = r11295 - r11297;
double r11299 = 0.225;
double r11300 = 2.0;
double r11301 = pow(r11286, r11300);
double r11302 = r11299 * r11301;
double r11303 = 0.009642857142857142;
double r11304 = 4.0;
double r11305 = pow(r11286, r11304);
double r11306 = r11303 * r11305;
double r11307 = 0.5;
double r11308 = r11306 + r11307;
double r11309 = r11302 - r11308;
double r11310 = r11292 ? r11298 : r11309;
return r11310;
}



Bits error versus x
Results
if x < -0.029017087826586654 or 0.031197100678935472 < x Initial program 0.0
rmApplied div-sub0.0
if -0.029017087826586654 < x < 0.031197100678935472Initial program 63.2
Taylor expanded around 0 0.0
Final simplification0.0
herbie shell --seed 2020083
(FPCore (x)
:name "sintan (problem 3.4.5)"
:precision binary64
(/ (- x (sin x)) (- x (tan x))))