\frac{x - \sin x}{x - \tan x}\begin{array}{l}
\mathbf{if}\;x \le -0.02880168700527437758429627479017653968185 \lor \neg \left(x \le 0.0265338026812843158497301487841468770057\right):\\
\;\;\;\;\frac{x}{x - \tan x} - \frac{\sin x}{x - \tan x}\\
\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 r12722 = x;
double r12723 = sin(r12722);
double r12724 = r12722 - r12723;
double r12725 = tan(r12722);
double r12726 = r12722 - r12725;
double r12727 = r12724 / r12726;
return r12727;
}
double f(double x) {
double r12728 = x;
double r12729 = -0.028801687005274378;
bool r12730 = r12728 <= r12729;
double r12731 = 0.026533802681284316;
bool r12732 = r12728 <= r12731;
double r12733 = !r12732;
bool r12734 = r12730 || r12733;
double r12735 = tan(r12728);
double r12736 = r12728 - r12735;
double r12737 = r12728 / r12736;
double r12738 = sin(r12728);
double r12739 = r12738 / r12736;
double r12740 = r12737 - r12739;
double r12741 = 0.225;
double r12742 = 2.0;
double r12743 = pow(r12728, r12742);
double r12744 = r12741 * r12743;
double r12745 = 0.009642857142857142;
double r12746 = 4.0;
double r12747 = pow(r12728, r12746);
double r12748 = r12745 * r12747;
double r12749 = r12744 - r12748;
double r12750 = 0.5;
double r12751 = r12749 - r12750;
double r12752 = r12734 ? r12740 : r12751;
return r12752;
}



Bits error versus x
Results
if x < -0.028801687005274378 or 0.026533802681284316 < x Initial program 0.0
rmApplied div-sub0.1
if -0.028801687005274378 < x < 0.026533802681284316Initial program 63.4
Taylor expanded around 0 0.0
rmApplied associate--r+0.0
Final simplification0.0
herbie shell --seed 2019350
(FPCore (x)
:name "sintan (problem 3.4.5)"
:precision binary64
(/ (- x (sin x)) (- x (tan x))))