\frac{x - \sin x}{x - \tan x}\begin{array}{l}
\mathbf{if}\;x \le \frac{-7640098872172261}{288230376151711744} \lor \neg \left(x \le \frac{2330914048531883}{72057594037927936}\right):\\
\;\;\;\;\frac{x - \sin x}{x - \tan x}\\
\mathbf{else}:\\
\;\;\;\;\frac{9}{40} \cdot {x}^{2} - \left(\left(\sqrt[3]{\frac{27}{2800} \cdot {x}^{4}} \cdot \sqrt[3]{\frac{27}{2800} \cdot {x}^{4}}\right) \cdot \sqrt[3]{\frac{27}{2800} \cdot {x}^{4}} + \frac{1}{2}\right)\\
\end{array}double f(double x) {
double r23542 = x;
double r23543 = sin(r23542);
double r23544 = r23542 - r23543;
double r23545 = tan(r23542);
double r23546 = r23542 - r23545;
double r23547 = r23544 / r23546;
return r23547;
}
double f(double x) {
double r23548 = x;
double r23549 = -7640098872172261.0;
double r23550 = 2.8823037615171174e+17;
double r23551 = r23549 / r23550;
bool r23552 = r23548 <= r23551;
double r23553 = 2330914048531883.0;
double r23554 = 7.205759403792794e+16;
double r23555 = r23553 / r23554;
bool r23556 = r23548 <= r23555;
double r23557 = !r23556;
bool r23558 = r23552 || r23557;
double r23559 = sin(r23548);
double r23560 = r23548 - r23559;
double r23561 = tan(r23548);
double r23562 = r23548 - r23561;
double r23563 = r23560 / r23562;
double r23564 = 0.225;
double r23565 = 2.0;
double r23566 = pow(r23548, r23565);
double r23567 = r23564 * r23566;
double r23568 = 0.009642857142857142;
double r23569 = 4.0;
double r23570 = pow(r23548, r23569);
double r23571 = r23568 * r23570;
double r23572 = cbrt(r23571);
double r23573 = r23572 * r23572;
double r23574 = r23573 * r23572;
double r23575 = 0.5;
double r23576 = r23574 + r23575;
double r23577 = r23567 - r23576;
double r23578 = r23558 ? r23563 : r23577;
return r23578;
}



Bits error versus x
Results
if x < -0.026506917744682296Initial program 0.1
if -0.026506917744682296 < x < 0.0323479305637792Initial program 63.2
Taylor expanded around 0 0.0
rmApplied add-cube-cbrt0.0
if 0.0323479305637792 < x Initial program 0.0
rmApplied div-sub0.0
Final simplification0.0
herbie shell --seed 197574269
(FPCore (x)
:name "sintan (problem 3.4.5)"
:precision binary64
(/ (- x (sin x)) (- x (tan x))))