\frac{x \cdot x - 3}{6}0.166666666666666657 \cdot {x}^{2} - 0.5double f(double x) {
double r123380 = x;
double r123381 = r123380 * r123380;
double r123382 = 3.0;
double r123383 = r123381 - r123382;
double r123384 = 6.0;
double r123385 = r123383 / r123384;
return r123385;
}
double f(double x) {
double r123386 = 0.16666666666666666;
double r123387 = x;
double r123388 = 2.0;
double r123389 = pow(r123387, r123388);
double r123390 = r123386 * r123389;
double r123391 = 0.5;
double r123392 = r123390 - r123391;
return r123392;
}



Bits error versus x
Results
Initial program 0.1
Taylor expanded around 0 0.2
Final simplification0.2
herbie shell --seed 2020042
(FPCore (x)
:name "Numeric.SpecFunctions:invIncompleteBetaWorker from math-functions-0.1.5.2, H"
:precision binary64
(/ (- (* x x) 3) 6))