\[\frac{x - \sin x}{x - \tan x}\]
Test:
NMSE problem 3.4.5
Bits:
128 bits
Bits error versus x
Time: 47.5 s
Input Error: 31.6
Output Error: 0.1
Log: ⚲
\(\begin{cases} \frac{x}{x - \tan x} - \frac{\sin x}{x - \tan x} & \text{when } x \le -3.150653682326084 \cdot 10^{-06} \\ \frac{9}{40} \cdot {x}^2 - \left(\frac{27}{2800} \cdot {x}^{4} + \frac{1}{2}\right) & \text{when } x \le 0.1680384430276768 \\ \frac{x}{x - \tan x} - \frac{\sin x}{x - \tan x} & \text{otherwise} \end{cases}\)

    if x < -3.150653682326084e-06 or 0.1680384430276768 < x

    1. Started with
      \[\frac{x - \sin x}{x - \tan x}\]
      0.2
    2. Using strategy rm
      0.2
    3. Applied div-sub to get
      \[\color{red}{\frac{x - \sin x}{x - \tan x}} \leadsto \color{blue}{\frac{x}{x - \tan x} - \frac{\sin x}{x - \tan x}}\]
      0.2

    if -3.150653682326084e-06 < x < 0.1680384430276768

    1. Started with
      \[\frac{x - \sin x}{x - \tan x}\]
      63.1
    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))))