\[\cos \left(x + \varepsilon\right) - \cos x\]
Test:
NMSE problem 3.3.5
Bits:
128 bits
Bits error versus x
Bits error versus eps
Time: 25.8 s
Input Error: 18.7
Output Error: 0.7
Log:
Profile: 🕒
\(\begin{cases} \log \left(e^{\cos \varepsilon \cdot \cos x - (\left(\sin \varepsilon\right) * \left(\sin x\right) + \left(\cos x\right))_*}\right) & \text{when } \varepsilon \le -0.008720061f0 \\ \frac{(\left(\sin x \cdot \sin x\right) * \left(\varepsilon \cdot \varepsilon\right) + \left(\left(\sin x \cdot \left(\varepsilon \cdot \frac{4}{3}\right)\right) \cdot \left(\cos x \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right))_* - (\left(\cos x\right) * \varepsilon + \left(\sin x \cdot 2\right))_* \cdot \left(\varepsilon \cdot \cos x\right)}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x} & \text{when } \varepsilon \le 0.019318156f0 \\ \frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\sin x \cdot \sin \varepsilon\right)}^2}{(\left(\sin x\right) * \left(\sin \varepsilon\right) + \left(\cos \varepsilon \cdot \cos x\right))_*} - \cos x & \text{otherwise} \end{cases}\)

    if eps < -0.008720061f0

    1. Started with
      \[\cos \left(x + \varepsilon\right) - \cos x\]
      14.7
    2. Using strategy rm
      14.7
    3. Applied cos-sum to get
      \[\color{red}{\cos \left(x + \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x\]
      0.9
    4. Using strategy rm
      0.9
    5. Applied add-log-exp to get
      \[\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) - \color{red}{\cos x} \leadsto \left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) - \color{blue}{\log \left(e^{\cos x}\right)}\]
      1.1
    6. Applied add-log-exp to get
      \[\left(\cos x \cdot \cos \varepsilon - \color{red}{\sin x \cdot \sin \varepsilon}\right) - \log \left(e^{\cos x}\right) \leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{\log \left(e^{\sin x \cdot \sin \varepsilon}\right)}\right) - \log \left(e^{\cos x}\right)\]
      1.2
    7. Applied add-log-exp to get
      \[\left(\color{red}{\cos x \cdot \cos \varepsilon} - \log \left(e^{\sin x \cdot \sin \varepsilon}\right)\right) - \log \left(e^{\cos x}\right) \leadsto \left(\color{blue}{\log \left(e^{\cos x \cdot \cos \varepsilon}\right)} - \log \left(e^{\sin x \cdot \sin \varepsilon}\right)\right) - \log \left(e^{\cos x}\right)\]
      1.4
    8. Applied diff-log to get
      \[\color{red}{\left(\log \left(e^{\cos x \cdot \cos \varepsilon}\right) - \log \left(e^{\sin x \cdot \sin \varepsilon}\right)\right)} - \log \left(e^{\cos x}\right) \leadsto \color{blue}{\log \left(\frac{e^{\cos x \cdot \cos \varepsilon}}{e^{\sin x \cdot \sin \varepsilon}}\right)} - \log \left(e^{\cos x}\right)\]
      1.4
    9. Applied diff-log to get
      \[\color{red}{\log \left(\frac{e^{\cos x \cdot \cos \varepsilon}}{e^{\sin x \cdot \sin \varepsilon}}\right) - \log \left(e^{\cos x}\right)} \leadsto \color{blue}{\log \left(\frac{\frac{e^{\cos x \cdot \cos \varepsilon}}{e^{\sin x \cdot \sin \varepsilon}}}{e^{\cos x}}\right)}\]
      1.4
    10. Applied simplify to get
      \[\log \color{red}{\left(\frac{\frac{e^{\cos x \cdot \cos \varepsilon}}{e^{\sin x \cdot \sin \varepsilon}}}{e^{\cos x}}\right)} \leadsto \log \color{blue}{\left(e^{\cos \varepsilon \cdot \cos x - (\left(\sin \varepsilon\right) * \left(\sin x\right) + \left(\cos x\right))_*}\right)}\]
      1.2

    if -0.008720061f0 < eps < 0.019318156f0

    1. Started with
      \[\cos \left(x + \varepsilon\right) - \cos x\]
      23.2
    2. Using strategy rm
      23.2
    3. Applied cos-sum to get
      \[\color{red}{\cos \left(x + \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x\]
      18.5
    4. Using strategy rm
      18.5
    5. Applied flip-- to get
      \[\color{red}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) - \cos x} \leadsto \color{blue}{\frac{{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)}^2 - {\left(\cos x\right)}^2}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) + \cos x}}\]
      18.5
    6. Applied simplify to get
      \[\frac{{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)}^2 - {\left(\cos x\right)}^2}{\color{red}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right) + \cos x}} \leadsto \frac{{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)}^2 - {\left(\cos x\right)}^2}{\color{blue}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x}}\]
      18.5
    7. Using strategy rm
      18.5
    8. Applied add-cbrt-cube to get
      \[\frac{\color{red}{{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)}^2 - {\left(\cos x\right)}^2}}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x} \leadsto \frac{\color{blue}{\sqrt[3]{{\left({\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)}^2 - {\left(\cos x\right)}^2\right)}^3}}}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x}\]
      18.8
    9. Applied taylor to get
      \[\frac{\sqrt[3]{{\left({\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)}^2 - {\left(\cos x\right)}^2\right)}^3}}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x} \leadsto \frac{\left(\frac{4}{3} \cdot \left({\varepsilon}^{3} \cdot \left(\sin x \cdot \cos x\right)\right) + {\varepsilon}^2 \cdot {\left(\sin x\right)}^2\right) - \left(2 \cdot \left(\varepsilon \cdot \left(\sin x \cdot \cos x\right)\right) + {\varepsilon}^2 \cdot {\left(\cos x\right)}^2\right)}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x}\]
      0.2
    10. Taylor expanded around 0 to get
      \[\frac{\color{red}{\left(\frac{4}{3} \cdot \left({\varepsilon}^{3} \cdot \left(\sin x \cdot \cos x\right)\right) + {\varepsilon}^2 \cdot {\left(\sin x\right)}^2\right) - \left(2 \cdot \left(\varepsilon \cdot \left(\sin x \cdot \cos x\right)\right) + {\varepsilon}^2 \cdot {\left(\cos x\right)}^2\right)}}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x} \leadsto \frac{\color{blue}{\left(\frac{4}{3} \cdot \left({\varepsilon}^{3} \cdot \left(\sin x \cdot \cos x\right)\right) + {\varepsilon}^2 \cdot {\left(\sin x\right)}^2\right) - \left(2 \cdot \left(\varepsilon \cdot \left(\sin x \cdot \cos x\right)\right) + {\varepsilon}^2 \cdot {\left(\cos x\right)}^2\right)}}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x}\]
      0.2
    11. Applied simplify to get
      \[\frac{\left(\frac{4}{3} \cdot \left({\varepsilon}^{3} \cdot \left(\sin x \cdot \cos x\right)\right) + {\varepsilon}^2 \cdot {\left(\sin x\right)}^2\right) - \left(2 \cdot \left(\varepsilon \cdot \left(\sin x \cdot \cos x\right)\right) + {\varepsilon}^2 \cdot {\left(\cos x\right)}^2\right)}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x} \leadsto \frac{(\left(\sin x \cdot \sin x\right) * \left(\varepsilon \cdot \varepsilon\right) + \left(\left(\left(\frac{4}{3} \cdot \varepsilon\right) \cdot \left(\varepsilon \cdot \varepsilon\right)\right) \cdot \left(\cos x \cdot \sin x\right)\right))_* - \cos x \cdot \left(\left(\varepsilon \cdot \varepsilon\right) \cdot \cos x + \left(2 \cdot \varepsilon\right) \cdot \sin x\right)}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x}\]
      0.2

    12. Applied final simplification
    13. Applied simplify to get
      \[\color{red}{\frac{(\left(\sin x \cdot \sin x\right) * \left(\varepsilon \cdot \varepsilon\right) + \left(\left(\left(\frac{4}{3} \cdot \varepsilon\right) \cdot \left(\varepsilon \cdot \varepsilon\right)\right) \cdot \left(\cos x \cdot \sin x\right)\right))_* - \cos x \cdot \left(\left(\varepsilon \cdot \varepsilon\right) \cdot \cos x + \left(2 \cdot \varepsilon\right) \cdot \sin x\right)}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x}} \leadsto \color{blue}{\frac{(\left(\sin x \cdot \sin x\right) * \left(\varepsilon \cdot \varepsilon\right) + \left(\left(\sin x \cdot \left(\varepsilon \cdot \frac{4}{3}\right)\right) \cdot \left(\cos x \cdot \left(\varepsilon \cdot \varepsilon\right)\right)\right))_* - (\left(\cos x\right) * \varepsilon + \left(\sin x \cdot 2\right))_* \cdot \left(\varepsilon \cdot \cos x\right)}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \sin x}}\]
      0.2

    if 0.019318156f0 < eps

    1. Started with
      \[\cos \left(x + \varepsilon\right) - \cos x\]
      14.5
    2. Using strategy rm
      14.5
    3. Applied cos-sum to get
      \[\color{red}{\cos \left(x + \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x\]
      0.8
    4. Using strategy rm
      0.8
    5. Applied flip-- to get
      \[\color{red}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \leadsto \color{blue}{\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\sin x \cdot \sin \varepsilon\right)}^2}{\cos x \cdot \cos \varepsilon + \sin x \cdot \sin \varepsilon}} - \cos x\]
      0.8
    6. Applied simplify to get
      \[\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\sin x \cdot \sin \varepsilon\right)}^2}{\color{red}{\cos x \cdot \cos \varepsilon + \sin x \cdot \sin \varepsilon}} - \cos x \leadsto \frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\sin x \cdot \sin \varepsilon\right)}^2}{\color{blue}{(\left(\sin x\right) * \left(\sin \varepsilon\right) + \left(\cos \varepsilon \cdot \cos x\right))_*}} - \cos x\]
      1.0

  1. Removed slow pow expressions

Original test:


(lambda ((x default) (eps default))
  #:name "NMSE problem 3.3.5"
  (- (cos (+ x eps)) (cos x)))