\frac{x - \sin x}{x - \tan x}\begin{array}{l}
\mathbf{if}\;x \le -0.0270579233257835539971924987412421614863 \lor \neg \left(x \le 0.03007487465186483091561520097911852644756\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 r20947 = x;
double r20948 = sin(r20947);
double r20949 = r20947 - r20948;
double r20950 = tan(r20947);
double r20951 = r20947 - r20950;
double r20952 = r20949 / r20951;
return r20952;
}
double f(double x) {
double r20953 = x;
double r20954 = -0.027057923325783554;
bool r20955 = r20953 <= r20954;
double r20956 = 0.03007487465186483;
bool r20957 = r20953 <= r20956;
double r20958 = !r20957;
bool r20959 = r20955 || r20958;
double r20960 = tan(r20953);
double r20961 = r20953 - r20960;
double r20962 = r20953 / r20961;
double r20963 = sin(r20953);
double r20964 = r20963 / r20961;
double r20965 = r20962 - r20964;
double r20966 = 0.225;
double r20967 = 2.0;
double r20968 = pow(r20953, r20967);
double r20969 = r20966 * r20968;
double r20970 = 0.009642857142857142;
double r20971 = 4.0;
double r20972 = pow(r20953, r20971);
double r20973 = r20970 * r20972;
double r20974 = 0.5;
double r20975 = r20973 + r20974;
double r20976 = r20969 - r20975;
double r20977 = r20959 ? r20965 : r20976;
return r20977;
}



Bits error versus x
Results
if x < -0.027057923325783554 or 0.03007487465186483 < x Initial program 0.1
rmApplied div-sub0.1
if -0.027057923325783554 < x < 0.03007487465186483Initial program 63.2
Taylor expanded around 0 0.0
Final simplification0.0
herbie shell --seed 2019303
(FPCore (x)
:name "sintan (problem 3.4.5)"
:precision binary64
(/ (- x (sin x)) (- x (tan x))))