\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x}\frac{1}{{\left(\tan x\right)}^{2} + 1} \cdot \left(1 - {\left(\tan x\right)}^{2}\right)(FPCore (x) :precision binary64 (/ (- 1.0 (* (tan x) (tan x))) (+ 1.0 (* (tan x) (tan x)))))
(FPCore (x) :precision binary64 (* (/ 1.0 (+ (pow (tan x) 2.0) 1.0)) (- 1.0 (pow (tan x) 2.0))))
double code(double x) {
return (((double) (1.0 - ((double) (((double) tan(x)) * ((double) tan(x)))))) / ((double) (1.0 + ((double) (((double) tan(x)) * ((double) tan(x)))))));
}
double code(double x) {
return ((double) ((1.0 / ((double) (((double) pow(((double) tan(x)), 2.0)) + 1.0))) * ((double) (1.0 - ((double) pow(((double) tan(x)), 2.0))))));
}



Bits error versus x
Results
Initial program 0.3
rmApplied add-sqr-sqrt0.3
Applied difference-of-squares0.4
Applied associate-/l*0.4
Simplified0.4
rmApplied div-inv0.4
Applied *-un-lft-identity0.4
Applied times-frac0.4
Simplified0.4
Final simplification0.4
herbie shell --seed 2020198
(FPCore (x)
:name "Trigonometry B"
:precision binary64
(/ (- 1.0 (* (tan x) (tan x))) (+ 1.0 (* (tan x) (tan x)))))