\[\frac{x - \sin x}{x - \tan x}\]
Test:
NMSE problem 3.4.5
Bits:
128 bits
Bits error versus x
Time: 22.4 s
Input Error: 31.8
Output Error: 0.3
Log: ⚲
Profile: 🕒
\(\begin{cases} \log_* (1 + (e^{\frac{x - \sin x}{x - \tan x}} - 1)^*) & \text{when } x \le -5.084423344895139 \cdot 10^{-11} \\ \frac{9}{40} \cdot {x}^2 - \left(\frac{27}{2800} \cdot {x}^{4} + \frac{1}{2}\right) & \text{when } x \le 0.9995081705491148 \\ \log_* (1 + (e^{\frac{x - \sin x}{x - \tan x}} - 1)^*) & \text{otherwise} \end{cases}\)

    if x < -5.084423344895139e-11 or 0.9995081705491148 < x

    1. Started with
      \[\frac{x - \sin x}{x - \tan x}\]
      0.6
    2. Using strategy rm
      0.6
    3. Applied log1p-expm1-u to get
      \[\color{red}{\frac{x - \sin x}{x - \tan x}} \leadsto \color{blue}{\log_* (1 + (e^{\frac{x - \sin x}{x - \tan x}} - 1)^*)}\]
      0.6

    if -5.084423344895139e-11 < x < 0.9995081705491148

    1. Started with
      \[\frac{x - \sin x}{x - \tan x}\]
      63.0
    2. Applied taylor to get
      \[\frac{x - \sin x}{x - \tan x} \leadsto \frac{9}{40} \cdot {x}^2 - \left(\frac{27}{2800} \cdot {x}^{4} + \frac{1}{2}\right)\]
      0.0
    3. Taylor expanded around 0 to get
      \[\color{red}{\frac{9}{40} \cdot {x}^2 - \left(\frac{27}{2800} \cdot {x}^{4} + \frac{1}{2}\right)} \leadsto \color{blue}{\frac{9}{40} \cdot {x}^2 - \left(\frac{27}{2800} \cdot {x}^{4} + \frac{1}{2}\right)}\]
      0.0
  1. Removed slow pow expressions

Original test:


(lambda ((x default))
  #:name "NMSE problem 3.4.5"
  (/ (- x (sin x)) (- x (tan x))))