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



Bits error versus x
Results
Initial program 0.3
rmApplied *-un-lft-identity_binary640.3
Applied add-sqr-sqrt_binary640.3
Applied difference-of-squares_binary640.4
Applied times-frac_binary640.4
Simplified0.4
Simplified0.4
rmApplied associate-*r/_binary640.4
Final simplification0.4
herbie shell --seed 2021205
(FPCore (x)
:name "Trigonometry B"
:precision binary64
(/ (- 1.0 (* (tan x) (tan x))) (+ 1.0 (* (tan x) (tan x)))))