\[{\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - {x}^{\left(\frac{1}{3}\right)}\]
Test:
NMSE problem 3.3.4
Bits:
128 bits
Bits error versus x
Time: 22.5 s
Input Error: 30.0
Output Error: 2.9
Log: ⚲
Profile: 🕒
\(\frac{1 - \left(\frac{1}{x} + \frac{-1}{x}\right)}{(\left({\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) * \left({x}^{\left(\frac{1}{3}\right)} + {\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) + \left({x}^{\left(\frac{1}{3}\right)} \cdot e^{\frac{\log x}{3}}\right))_*}\)
  1. Started with
    \[{\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - {x}^{\left(\frac{1}{3}\right)}\]
    30.0
  2. Using strategy rm
    30.0
  3. Applied flip3-- to get
    \[\color{red}{{\left(x + 1\right)}^{\left(\frac{1}{3}\right)} - {x}^{\left(\frac{1}{3}\right)}} \leadsto \color{blue}{\frac{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^{3} - {\left({x}^{\left(\frac{1}{3}\right)}\right)}^{3}}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^2 + \left({\left({x}^{\left(\frac{1}{3}\right)}\right)}^2 + {\left(x + 1\right)}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right)}}\]
    29.9
  4. Applied simplify to get
    \[\frac{\color{red}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^{3} - {\left({x}^{\left(\frac{1}{3}\right)}\right)}^{3}}}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^2 + \left({\left({x}^{\left(\frac{1}{3}\right)}\right)}^2 + {\left(x + 1\right)}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right)} \leadsto \frac{\color{blue}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^3 - {\left({x}^{\left(\frac{1}{3}\right)}\right)}^3}}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^2 + \left({\left({x}^{\left(\frac{1}{3}\right)}\right)}^2 + {\left(x + 1\right)}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right)}\]
    30.0
  5. Applied taylor to get
    \[\frac{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^3 - {\left({x}^{\left(\frac{1}{3}\right)}\right)}^3}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^2 + \left({\left({x}^{\left(\frac{1}{3}\right)}\right)}^2 + {\left(x + 1\right)}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right)} \leadsto \frac{{\left({\left(1 - \frac{1}{x}\right)}^{\frac{1}{3}}\right)}^3 - {\left({\left(\frac{-1}{x}\right)}^{\frac{1}{3}}\right)}^3}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^2 + \left({\left({x}^{\left(\frac{1}{3}\right)}\right)}^2 + {\left(x + 1\right)}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right)}\]
    62.2
  6. Taylor expanded around -inf to get
    \[\frac{\color{red}{{\left({\left(1 - \frac{1}{x}\right)}^{\frac{1}{3}}\right)}^3 - {\left({\left(\frac{-1}{x}\right)}^{\frac{1}{3}}\right)}^3}}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^2 + \left({\left({x}^{\left(\frac{1}{3}\right)}\right)}^2 + {\left(x + 1\right)}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right)} \leadsto \frac{\color{blue}{{\left({\left(1 - \frac{1}{x}\right)}^{\frac{1}{3}}\right)}^3 - {\left({\left(\frac{-1}{x}\right)}^{\frac{1}{3}}\right)}^3}}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^2 + \left({\left({x}^{\left(\frac{1}{3}\right)}\right)}^2 + {\left(x + 1\right)}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right)}\]
    62.2
  7. Applied simplify to get
    \[\color{red}{\frac{{\left({\left(1 - \frac{1}{x}\right)}^{\frac{1}{3}}\right)}^3 - {\left({\left(\frac{-1}{x}\right)}^{\frac{1}{3}}\right)}^3}{{\left({\left(x + 1\right)}^{\left(\frac{1}{3}\right)}\right)}^2 + \left({\left({x}^{\left(\frac{1}{3}\right)}\right)}^2 + {\left(x + 1\right)}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right)}} \leadsto \color{blue}{\frac{1 - \left(\frac{1}{x} + \frac{-1}{x}\right)}{(\left({\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) * \left({x}^{\left(\frac{1}{3}\right)} + {\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) + \left({x}^{\left(\frac{1}{3}\right)} \cdot {x}^{\left(\frac{1}{3}\right)}\right))_*}}\]
    3.1
  8. Using strategy rm
    3.1
  9. Applied pow-to-exp to get
    \[\frac{1 - \left(\frac{1}{x} + \frac{-1}{x}\right)}{(\left({\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) * \left({x}^{\left(\frac{1}{3}\right)} + {\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) + \left({x}^{\left(\frac{1}{3}\right)} \cdot \color{red}{{x}^{\left(\frac{1}{3}\right)}}\right))_*} \leadsto \frac{1 - \left(\frac{1}{x} + \frac{-1}{x}\right)}{(\left({\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) * \left({x}^{\left(\frac{1}{3}\right)} + {\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) + \left({x}^{\left(\frac{1}{3}\right)} \cdot \color{blue}{e^{\log x \cdot \frac{1}{3}}}\right))_*}\]
    3.1
  10. Applied simplify to get
    \[\frac{1 - \left(\frac{1}{x} + \frac{-1}{x}\right)}{(\left({\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) * \left({x}^{\left(\frac{1}{3}\right)} + {\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) + \left({x}^{\left(\frac{1}{3}\right)} \cdot e^{\color{red}{\log x \cdot \frac{1}{3}}}\right))_*} \leadsto \frac{1 - \left(\frac{1}{x} + \frac{-1}{x}\right)}{(\left({\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) * \left({x}^{\left(\frac{1}{3}\right)} + {\left(1 + x\right)}^{\left(\frac{1}{3}\right)}\right) + \left({x}^{\left(\frac{1}{3}\right)} \cdot e^{\color{blue}{\frac{\log x}{3}}}\right))_*}\]
    2.9

Original test:


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