\[\cos \left(x + \varepsilon\right) - \cos x\]
Test:
NMSE problem 3.3.5
Bits:
128 bits
Bits error versus x
Bits error versus eps
Time: 30.6 s
Input Error: 39.4
Output Error: 0.5
Log:
Profile: 🕒
\(\begin{cases} \frac{(\left(-\sin \varepsilon\right) * \left(\sin x\right) + \left(\cos x \cdot \cos \varepsilon\right))_* - \cos x}{\frac{(\left(\cos x\right) * \left(\cos \varepsilon\right) + \left(\cos x\right))_* - \left(-\sin x \cdot \sin \varepsilon\right)}{(\left(\cos x\right) * \left(\cos \varepsilon\right) + \left(\cos x\right))_* - \left(-\sin x \cdot \sin \varepsilon\right)}} & \text{when } \varepsilon \le -8.102966659834604 \cdot 10^{-08} \\ {\varepsilon}^3 \cdot \left(\frac{1}{6} \cdot \sin x\right) - \varepsilon \cdot (\frac{1}{2} * \varepsilon + \left(\sin x\right))_* & \text{when } \varepsilon \le 0.0009667373424041872 \\ (\left(\cos x\right) * \left(\cos \varepsilon\right) + \left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right))_* & \text{otherwise} \end{cases}\)

    if eps < -8.102966659834604e-08

    1. Started with
      \[\cos \left(x + \varepsilon\right) - \cos x\]
      29.7
    2. Using strategy rm
      29.7
    3. Applied cos-sum to get
      \[\color{red}{\cos \left(x + \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x\]
      1.1
    4. Using strategy rm
      1.1
    5. Applied sub-neg to get
      \[\color{red}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x \cdot \sin \varepsilon\right)\right)} - \cos x\]
      1.1
    6. Applied associate--l+ to get
      \[\color{red}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x \cdot \sin \varepsilon\right)\right) - \cos x} \leadsto \color{blue}{\cos x \cdot \cos \varepsilon + \left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}\]
      1.1
    7. Using strategy rm
      1.1
    8. Applied flip-+ to get
      \[\color{red}{\cos x \cdot \cos \varepsilon + \left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)} \leadsto \color{blue}{\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}^2}{\cos x \cdot \cos \varepsilon - \left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}}\]
      1.6
    9. Applied simplify to get
      \[\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}^2}{\color{red}{\cos x \cdot \cos \varepsilon - \left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}} \leadsto \frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}^2}{\color{blue}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin x \cdot \left(-\sin \varepsilon\right)}}\]
      1.7
    10. Applied taylor to get
      \[\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}^2}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin x \cdot \left(-\sin \varepsilon\right)} \leadsto \frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}^2}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin x \cdot \left(-\sin \varepsilon\right)}\]
      1.7
    11. Taylor expanded around 0 to get
      \[\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}^2}{\color{red}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_*} - \sin x \cdot \left(-\sin \varepsilon\right)} \leadsto \frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}^2}{\color{blue}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_*} - \sin x \cdot \left(-\sin \varepsilon\right)}\]
      1.7
    12. Applied simplify to get
      \[\frac{{\left(\cos x \cdot \cos \varepsilon\right)}^2 - {\left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}^2}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin x \cdot \left(-\sin \varepsilon\right)} \leadsto \frac{\sin \varepsilon \cdot \left(-\sin x\right) - \left(\cos x - \cos \varepsilon \cdot \cos x\right)}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \left(-\sin x\right)} \cdot \left(\cos \varepsilon \cdot \cos x - \left(\sin \varepsilon \cdot \left(-\sin x\right) - \cos x\right)\right)\]
      1.4

    13. Applied final simplification
    14. Applied simplify to get
      \[\color{red}{\frac{\sin \varepsilon \cdot \left(-\sin x\right) - \left(\cos x - \cos \varepsilon \cdot \cos x\right)}{(\left(\cos \varepsilon\right) * \left(\cos x\right) + \left(\cos x\right))_* - \sin \varepsilon \cdot \left(-\sin x\right)} \cdot \left(\cos \varepsilon \cdot \cos x - \left(\sin \varepsilon \cdot \left(-\sin x\right) - \cos x\right)\right)} \leadsto \color{blue}{\frac{(\left(-\sin \varepsilon\right) * \left(\sin x\right) + \left(\cos x \cdot \cos \varepsilon\right))_* - \cos x}{\frac{(\left(\cos x\right) * \left(\cos \varepsilon\right) + \left(\cos x\right))_* - \left(-\sin x \cdot \sin \varepsilon\right)}{(\left(\cos x\right) * \left(\cos \varepsilon\right) + \left(\cos x\right))_* - \left(-\sin x \cdot \sin \varepsilon\right)}}}\]
      1.1

    if -8.102966659834604e-08 < eps < 0.0009667373424041872

    1. Started with
      \[\cos \left(x + \varepsilon\right) - \cos x\]
      49.7
    2. Using strategy rm
      49.7
    3. Applied cos-sum to get
      \[\color{red}{\cos \left(x + \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x\]
      49.3
    4. Using strategy rm
      49.3
    5. Applied add-cube-cbrt to get
      \[\left(\cos x \cdot \cos \varepsilon - \color{red}{\sin x \cdot \sin \varepsilon}\right) - \cos x \leadsto \left(\cos x \cdot \cos \varepsilon - \color{blue}{{\left(\sqrt[3]{\sin x \cdot \sin \varepsilon}\right)}^3}\right) - \cos x\]
      49.3
    6. Applied taylor to get
      \[\left(\cos x \cdot \cos \varepsilon - {\left(\sqrt[3]{\sin x \cdot \sin \varepsilon}\right)}^3\right) - \cos x \leadsto \frac{1}{6} \cdot \left({\varepsilon}^{3} \cdot \sin x\right) - \left(\frac{1}{2} \cdot {\varepsilon}^2 + \varepsilon \cdot \sin x\right)\]
      0.1
    7. Taylor expanded around 0 to get
      \[\color{red}{\frac{1}{6} \cdot \left({\varepsilon}^{3} \cdot \sin x\right) - \left(\frac{1}{2} \cdot {\varepsilon}^2 + \varepsilon \cdot \sin x\right)} \leadsto \color{blue}{\frac{1}{6} \cdot \left({\varepsilon}^{3} \cdot \sin x\right) - \left(\frac{1}{2} \cdot {\varepsilon}^2 + \varepsilon \cdot \sin x\right)}\]
      0.1
    8. Applied simplify to get
      \[\frac{1}{6} \cdot \left({\varepsilon}^{3} \cdot \sin x\right) - \left(\frac{1}{2} \cdot {\varepsilon}^2 + \varepsilon \cdot \sin x\right) \leadsto \frac{1}{6} \cdot \left({\varepsilon}^3 \cdot \sin x\right) - \varepsilon \cdot \left(\sin x + \frac{1}{2} \cdot \varepsilon\right)\]
      0.1

    9. Applied final simplification
    10. Applied simplify to get
      \[\color{red}{\frac{1}{6} \cdot \left({\varepsilon}^3 \cdot \sin x\right) - \varepsilon \cdot \left(\sin x + \frac{1}{2} \cdot \varepsilon\right)} \leadsto \color{blue}{{\varepsilon}^3 \cdot \left(\frac{1}{6} \cdot \sin x\right) - \varepsilon \cdot (\frac{1}{2} * \varepsilon + \left(\sin x\right))_*}\]
      0.1

    if 0.0009667373424041872 < eps

    1. Started with
      \[\cos \left(x + \varepsilon\right) - \cos x\]
      29.2
    2. Using strategy rm
      29.2
    3. Applied cos-sum to get
      \[\color{red}{\cos \left(x + \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x\]
      0.8
    4. Using strategy rm
      0.8
    5. Applied sub-neg to get
      \[\color{red}{\left(\cos x \cdot \cos \varepsilon - \sin x \cdot \sin \varepsilon\right)} - \cos x \leadsto \color{blue}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x \cdot \sin \varepsilon\right)\right)} - \cos x\]
      0.8
    6. Applied associate--l+ to get
      \[\color{red}{\left(\cos x \cdot \cos \varepsilon + \left(-\sin x \cdot \sin \varepsilon\right)\right) - \cos x} \leadsto \color{blue}{\cos x \cdot \cos \varepsilon + \left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)}\]
      0.8
    7. Using strategy rm
      0.8
    8. Applied fma-def to get
      \[\color{red}{\cos x \cdot \cos \varepsilon + \left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right)} \leadsto \color{blue}{(\left(\cos x\right) * \left(\cos \varepsilon\right) + \left(\left(-\sin x \cdot \sin \varepsilon\right) - \cos x\right))_*}\]
      0.8

  1. Removed slow pow expressions

Original test:


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