Average Error: 29.6 → 0.5
Time: 2.6m
Precision: 64
Internal Precision: 1344
\[\frac{x}{x + 1} - \frac{x + 1}{x - 1}\]
\[\begin{array}{l} \mathbf{if}\;\frac{-3}{x} - \frac{1 + \frac{3}{x}}{x \cdot x} \le -4.255266848050538 \cdot 10^{-06}:\\ \;\;\;\;\frac{x}{1 + x} - \left(x \cdot x + \left(1 + x\right)\right) \cdot \frac{1 + x}{{x}^{3} - 1}\\ \mathbf{if}\;\frac{-3}{x} - \frac{1 + \frac{3}{x}}{x \cdot x} \le 4.259164918451753 \cdot 10^{-19}:\\ \;\;\;\;\frac{-3}{x} - \frac{1 + \frac{3}{x}}{x \cdot x}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\left(x \cdot x\right) \cdot \left(x - 1\right) - {\left(1 + x\right)}^{3} \cdot \frac{1 + x}{x - 1}}{\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(x - 1\right)}}{\frac{x}{1 + x} + \frac{1 + x}{x - 1}}\\ \end{array}\]

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 3 regimes
  2. if (- (/ (- 3) x) (/ (+ 1 (/ 3 x)) (* x x))) < -4.255266848050538e-06

    1. Initial program 0.1

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1}\]
    2. Using strategy rm
    3. Applied flip3--0.1

      \[\leadsto \frac{x}{x + 1} - \frac{x + 1}{\color{blue}{\frac{{x}^{3} - {1}^{3}}{x \cdot x + \left(1 \cdot 1 + x \cdot 1\right)}}}\]
    4. Applied associate-/r/0.1

      \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{x + 1}{{x}^{3} - {1}^{3}} \cdot \left(x \cdot x + \left(1 \cdot 1 + x \cdot 1\right)\right)}\]
    5. Applied simplify0.1

      \[\leadsto \frac{x}{x + 1} - \color{blue}{\frac{1 + x}{{x}^{3} - 1}} \cdot \left(x \cdot x + \left(1 \cdot 1 + x \cdot 1\right)\right)\]

    if -4.255266848050538e-06 < (- (/ (- 3) x) (/ (+ 1 (/ 3 x)) (* x x))) < 4.259164918451753e-19

    1. Initial program 60.0

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1}\]
    2. Taylor expanded around inf 0.3

      \[\leadsto \color{blue}{-\left(3 \cdot \frac{1}{{x}^{3}} + \left(3 \cdot \frac{1}{x} + \frac{1}{{x}^{2}}\right)\right)}\]
    3. Applied simplify0.0

      \[\leadsto \color{blue}{\frac{-3}{x} - \frac{1 + \frac{3}{x}}{x \cdot x}}\]

    if 4.259164918451753e-19 < (- (/ (- 3) x) (/ (+ 1 (/ 3 x)) (* x x)))

    1. Initial program 1.6

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1}\]
    2. Using strategy rm
    3. Applied flip--1.6

      \[\leadsto \color{blue}{\frac{\frac{x}{x + 1} \cdot \frac{x}{x + 1} - \frac{x + 1}{x - 1} \cdot \frac{x + 1}{x - 1}}{\frac{x}{x + 1} + \frac{x + 1}{x - 1}}}\]
    4. Using strategy rm
    5. Applied associate-*r/1.6

      \[\leadsto \frac{\frac{x}{x + 1} \cdot \frac{x}{x + 1} - \color{blue}{\frac{\frac{x + 1}{x - 1} \cdot \left(x + 1\right)}{x - 1}}}{\frac{x}{x + 1} + \frac{x + 1}{x - 1}}\]
    6. Applied frac-times1.6

      \[\leadsto \frac{\color{blue}{\frac{x \cdot x}{\left(x + 1\right) \cdot \left(x + 1\right)}} - \frac{\frac{x + 1}{x - 1} \cdot \left(x + 1\right)}{x - 1}}{\frac{x}{x + 1} + \frac{x + 1}{x - 1}}\]
    7. Applied frac-sub1.6

      \[\leadsto \frac{\color{blue}{\frac{\left(x \cdot x\right) \cdot \left(x - 1\right) - \left(\left(x + 1\right) \cdot \left(x + 1\right)\right) \cdot \left(\frac{x + 1}{x - 1} \cdot \left(x + 1\right)\right)}{\left(\left(x + 1\right) \cdot \left(x + 1\right)\right) \cdot \left(x - 1\right)}}}{\frac{x}{x + 1} + \frac{x + 1}{x - 1}}\]
    8. Applied simplify1.6

      \[\leadsto \frac{\frac{\color{blue}{\left(x - 1\right) \cdot \left(x \cdot x\right) - \frac{x + 1}{x - 1} \cdot {\left(x + 1\right)}^{3}}}{\left(\left(x + 1\right) \cdot \left(x + 1\right)\right) \cdot \left(x - 1\right)}}{\frac{x}{x + 1} + \frac{x + 1}{x - 1}}\]
  3. Recombined 3 regimes into one program.
  4. Applied simplify0.5

    \[\leadsto \color{blue}{\begin{array}{l} \mathbf{if}\;\frac{-3}{x} - \frac{1 + \frac{3}{x}}{x \cdot x} \le -4.255266848050538 \cdot 10^{-06}:\\ \;\;\;\;\frac{x}{1 + x} - \left(x \cdot x + \left(1 + x\right)\right) \cdot \frac{1 + x}{{x}^{3} - 1}\\ \mathbf{if}\;\frac{-3}{x} - \frac{1 + \frac{3}{x}}{x \cdot x} \le 4.259164918451753 \cdot 10^{-19}:\\ \;\;\;\;\frac{-3}{x} - \frac{1 + \frac{3}{x}}{x \cdot x}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\left(x \cdot x\right) \cdot \left(x - 1\right) - {\left(1 + x\right)}^{3} \cdot \frac{1 + x}{x - 1}}{\left(\left(1 + x\right) \cdot \left(1 + x\right)\right) \cdot \left(x - 1\right)}}{\frac{x}{1 + x} + \frac{1 + x}{x - 1}}\\ \end{array}}\]

Runtime

Time bar (total: 2.6m)Debug logProfile

herbie shell --seed 2018178 
(FPCore (x)
  :name "Asymptote C"
  (- (/ x (+ x 1)) (/ (+ x 1) (- x 1))))