Average Error: 0.2 → 0.1
Time: 15.7s
Precision: 64
\[3.0 \cdot \left(\left(\left(x \cdot 3.0\right) \cdot x - x \cdot 4.0\right) + 1.0\right)\]
↓
\[\left(x \cdot 9.0 - 12.0\right) \cdot x + 3.0\]
3.0 \cdot \left(\left(\left(x \cdot 3.0\right) \cdot x - x \cdot 4.0\right) + 1.0\right)
↓
\left(x \cdot 9.0 - 12.0\right) \cdot x + 3.0
double f(double x) {
        double r39065060 = 3.0;
        double r39065061 = x;
        double r39065062 = r39065061 * r39065060;
        double r39065063 = r39065062 * r39065061;
        double r39065064 = 4.0;
        double r39065065 = r39065061 * r39065064;
        double r39065066 = r39065063 - r39065065;
        double r39065067 = 1.0;
        double r39065068 = r39065066 + r39065067;
        double r39065069 = r39065060 * r39065068;
        return r39065069;
}
↓
double f(double x) {
        double r39065070 = x;
        double r39065071 = 9.0;
        double r39065072 = r39065070 * r39065071;
        double r39065073 = 12.0;
        double r39065074 = r39065072 - r39065073;
        double r39065075 = r39065074 * r39065070;
        double r39065076 = 3.0;
        double r39065077 = r39065075 + r39065076;
        return r39065077;
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original0.2
Target0.1
Herbie0.1
\[3.0 + \left(\left(9.0 \cdot x\right) \cdot x - 12.0 \cdot x\right)\]

Derivation

  1. Initial program 0.2

    \[3.0 \cdot \left(\left(\left(x \cdot 3.0\right) \cdot x - x \cdot 4.0\right) + 1.0\right)\]

  2. Simplified0.2

    \[\leadsto \color{blue}{3.0 \cdot \left(1.0 - \left(4.0 - x \cdot 3.0\right) \cdot x\right)}\]

  3. Taylor expanded around 0 0.1

    \[\leadsto \color{blue}{\left(9.0 \cdot {x}^{2} + 3.0\right) - 12.0 \cdot x}\]

  4. Simplified0.1

    \[\leadsto \color{blue}{x \cdot \left(x \cdot 9.0 - 12.0\right) + 3.0}\]

  5. Final simplification0.1

    \[\leadsto \left(x \cdot 9.0 - 12.0\right) \cdot x + 3.0\]

Reproduce

herbie shell --seed 2019163 
(FPCore (x)
  :name "Diagrams.Tangent:$catParam from diagrams-lib-1.3.0.3, D"

  :herbie-target
  (+ 3.0 (- (* (* 9.0 x) x) (* 12.0 x)))

  (* 3.0 (+ (- (* (* x 3.0) x) (* x 4.0)) 1.0)))