\[{\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - {x}^{\left(\frac{1}{3}\right)}\]
Test:
NMSE problem 3.3.4
Bits:
128 bits
Bits error versus x
Time: 16.8 s
Input Error: 13.1
Output Error: 13.0
Log:
Profile: 🕒
\(\left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) \cdot \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{\sqrt[3]{x}}\right)\)
  1. Started with
    \[{\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - {x}^{\left(\frac{1}{3}\right)}\]
    13.1
  2. Using strategy rm
    13.1
  3. Applied add-exp-log to get
    \[\color{red}{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - {x}^{\left(\frac{1}{3}\right)}} \leadsto \color{blue}{e^{\log \left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - {x}^{\left(\frac{1}{3}\right)}\right)}}\]
    13.1
  4. Using strategy rm
    13.1
  5. Applied add-sqr-sqrt to get
    \[e^{\log \left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - \color{red}{{x}^{\left(\frac{1}{3}\right)}}\right)} \leadsto e^{\log \left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - \color{blue}{{\left(\sqrt{{x}^{\left(\frac{1}{3}\right)}}\right)}^2}\right)}\]
    13.3
  6. Applied add-sqr-sqrt to get
    \[e^{\log \left(\color{red}{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - {\left(\sqrt{{x}^{\left(\frac{1}{3}\right)}}\right)}^2\right)} \leadsto e^{\log \left(\color{blue}{{\left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}}\right)}^2} - {\left(\sqrt{{x}^{\left(\frac{1}{3}\right)}}\right)}^2\right)}\]
    13.3
  7. Applied difference-of-squares to get
    \[e^{\log \color{red}{\left({\left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}}\right)}^2 - {\left(\sqrt{{x}^{\left(\frac{1}{3}\right)}}\right)}^2\right)}} \leadsto e^{\log \color{blue}{\left(\left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) \cdot \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right)\right)}}\]
    13.3
  8. Applied log-prod to get
    \[e^{\color{red}{\log \left(\left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) \cdot \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right)\right)}} \leadsto e^{\color{blue}{\log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) + \log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right)}}\]
    13.4
  9. Applied taylor to get
    \[e^{\log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) + \log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right)} \leadsto e^{\log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) + \log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{{x}^{\frac{1}{3}}}\right)}\]
    13.4
  10. Taylor expanded around 0 to get
    \[e^{\log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) + \log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{\color{red}{{x}^{\frac{1}{3}}}}\right)} \leadsto e^{\log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) + \log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{\color{blue}{{x}^{\frac{1}{3}}}}\right)}\]
    13.4
  11. Applied simplify to get
    \[e^{\log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) + \log \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{{x}^{\frac{1}{3}}}\right)} \leadsto \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} + \sqrt{{x}^{\left(\frac{1}{3}\right)}}\right) \cdot \left(\sqrt{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)}} - \sqrt{\sqrt[3]{x}}\right)\]
    13.0

  12. Applied final simplification

Original test:


(lambda ((x default))
  #:name "NMSE problem 3.3.4"
  (- (pow (+ x 1) (/ 1 3)) (pow x (/ 1 3))))