\tan \left(x + \varepsilon\right) - \tan x
\frac{\sin \varepsilon}{\cos \varepsilon \cdot \left(1 - \frac{\sin x}{\cos x} \cdot \left(\sqrt[3]{\frac{\sin \varepsilon}{\cos \varepsilon}} \cdot \left(\sqrt[3]{\frac{\sin \varepsilon}{\cos \varepsilon}} \cdot \sqrt[3]{\frac{\sin \varepsilon}{\cos \varepsilon}}\right)\right)\right)} + \frac{\frac{\sin x}{1 - \frac{\sin \varepsilon}{\cos x} \cdot \frac{\sin x}{\cos \varepsilon}} - \sin x}{\cos x}double f(double x, double eps) {
double r67503 = x;
double r67504 = eps;
double r67505 = r67503 + r67504;
double r67506 = tan(r67505);
double r67507 = tan(r67503);
double r67508 = r67506 - r67507;
return r67508;
}
double f(double x, double eps) {
double r67509 = eps;
double r67510 = sin(r67509);
double r67511 = cos(r67509);
double r67512 = 1.0;
double r67513 = x;
double r67514 = sin(r67513);
double r67515 = cos(r67513);
double r67516 = r67514 / r67515;
double r67517 = r67510 / r67511;
double r67518 = cbrt(r67517);
double r67519 = r67518 * r67518;
double r67520 = r67518 * r67519;
double r67521 = r67516 * r67520;
double r67522 = r67512 - r67521;
double r67523 = r67511 * r67522;
double r67524 = r67510 / r67523;
double r67525 = r67510 / r67515;
double r67526 = r67514 / r67511;
double r67527 = r67525 * r67526;
double r67528 = r67512 - r67527;
double r67529 = r67514 / r67528;
double r67530 = r67529 - r67514;
double r67531 = r67530 / r67515;
double r67532 = r67524 + r67531;
return r67532;
}




Bits error versus x




Bits error versus eps
Results
| Original | 37.2 |
|---|---|
| Target | 15.7 |
| Herbie | 12.9 |
Initial program 37.2
rmApplied tan-sum21.5
Simplified21.5
Taylor expanded around inf 21.7
Simplified12.8
rmApplied sub-div12.8
Simplified12.8
rmApplied add-cube-cbrt12.9
Final simplification12.9
herbie shell --seed 2019179
(FPCore (x eps)
:name "2tan (problem 3.3.2)"
:herbie-target
(/ (sin eps) (* (cos x) (cos (+ x eps))))
(- (tan (+ x eps)) (tan x)))