\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x}\log \left(e^{\frac{1}{\tan x \cdot \tan x + 1} - \frac{\tan x \cdot \tan x}{\tan x \cdot \tan x + 1}}\right)double f(double x) {
double r1450468 = 1.0;
double r1450469 = x;
double r1450470 = tan(r1450469);
double r1450471 = r1450470 * r1450470;
double r1450472 = r1450468 - r1450471;
double r1450473 = r1450468 + r1450471;
double r1450474 = r1450472 / r1450473;
return r1450474;
}
double f(double x) {
double r1450475 = 1.0;
double r1450476 = x;
double r1450477 = tan(r1450476);
double r1450478 = r1450477 * r1450477;
double r1450479 = r1450478 + r1450475;
double r1450480 = r1450475 / r1450479;
double r1450481 = r1450478 / r1450479;
double r1450482 = r1450480 - r1450481;
double r1450483 = exp(r1450482);
double r1450484 = log(r1450483);
return r1450484;
}



Bits error versus x
Results
Initial program 0.3
rmApplied add-log-exp0.4
rmApplied div-sub0.5
Final simplification0.5
herbie shell --seed 2019119
(FPCore (x)
:name "Trigonometry B"
(/ (- 1 (* (tan x) (tan x))) (+ 1 (* (tan x) (tan x)))))