Average Error: 0.2 → 1.0
Time: 2.9s
Precision: binary64
\[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1\]
↓
\[\left({b}^{4} + \left({a}^{4} + a \cdot \left(a \cdot \left(b \cdot \left(b \cdot 2\right)\right)\right)\right)\right) - 1\]
\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1
↓
\left({b}^{4} + \left({a}^{4} + a \cdot \left(a \cdot \left(b \cdot \left(b \cdot 2\right)\right)\right)\right)\right) - 1
double code(double a, double b) {
	return ((double) (((double) (((double) pow(((double) (((double) (a * a)) + ((double) (b * b)))), 2.0)) + ((double) (4.0 * ((double) (b * b)))))) - 1.0));
}
↓
double code(double a, double b) {
	return ((double) (((double) (((double) pow(b, 4.0)) + ((double) (((double) pow(a, 4.0)) + ((double) (a * ((double) (a * ((double) (b * ((double) (b * 2.0)))))))))))) - 1.0));
}

Error

Bits error versus a

Bits error versus b

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 0.2

    \[\left({\left(a \cdot a + b \cdot b\right)}^{2} + 4 \cdot \left(b \cdot b\right)\right) - 1\]

  2. Taylor expanded around inf 1.0

    \[\leadsto \color{blue}{\left({a}^{4} + \left({b}^{4} + 2 \cdot \left({a}^{2} \cdot {b}^{2}\right)\right)\right)} - 1\]

  3. Simplified1.0

    \[\leadsto \color{blue}{\left({b}^{4} + \left({a}^{4} + a \cdot \left(a \cdot \left(b \cdot \left(b \cdot 2\right)\right)\right)\right)\right)} - 1\]

  4. Final simplification1.0

    \[\leadsto \left({b}^{4} + \left({a}^{4} + a \cdot \left(a \cdot \left(b \cdot \left(b \cdot 2\right)\right)\right)\right)\right) - 1\]

Reproduce

herbie shell --seed 2020196 
(FPCore (a b)
  :name "Bouland and Aaronson, Equation (26)"
  :precision binary64
  (- (+ (pow (+ (* a a) (* b b)) 2.0) (* 4.0 (* b b))) 1.0))