\[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
Test:
Complex division, real part
Bits:
128 bits
Bits error versus a
Bits error versus b
Bits error versus c
Bits error versus d
Time: 16.5 s
Input Error: 27.3
Output Error: 11.2
Log:
Profile: 🕒
\(\begin{cases} \frac{a}{c} + \frac{b}{c} \cdot \frac{d}{c} & \text{when } c \le -1.3770151188228676 \cdot 10^{+30} \\ \frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2} & \text{when } c \le 1.745403512153814 \cdot 10^{-141} \\ \left(\frac{a}{d} \cdot \frac{c}{d} + \frac{b}{d}\right) - \frac{b}{{d}^3 \cdot {c}^2} & \text{when } c \le 4.1244432764021164 \cdot 10^{-110} \\ \frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2} & \text{when } c \le 4.6559433524913966 \cdot 10^{+129} \\ \frac{a}{c} + \frac{b}{c} \cdot \frac{d}{c} & \text{otherwise} \end{cases}\)

    if c < -1.3770151188228676e+30 or 4.6559433524913966e+129 < c

    1. Started with
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
      39.8
    2. Using strategy rm
      39.8
    3. Applied clear-num to get
      \[\color{red}{\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}} \leadsto \color{blue}{\frac{1}{\frac{{c}^2 + {d}^2}{a \cdot c + b \cdot d}}}\]
      39.8
    4. Using strategy rm
      39.8
    5. Applied div-inv to get
      \[\frac{1}{\color{red}{\frac{{c}^2 + {d}^2}{a \cdot c + b \cdot d}}} \leadsto \frac{1}{\color{blue}{\left({c}^2 + {d}^2\right) \cdot \frac{1}{a \cdot c + b \cdot d}}}\]
      39.9
    6. Applied associate-/r* to get
      \[\color{red}{\frac{1}{\left({c}^2 + {d}^2\right) \cdot \frac{1}{a \cdot c + b \cdot d}}} \leadsto \color{blue}{\frac{\frac{1}{{c}^2 + {d}^2}}{\frac{1}{a \cdot c + b \cdot d}}}\]
      39.8
    7. Using strategy rm
      39.8
    8. Applied add-cbrt-cube to get
      \[\frac{\color{red}{\frac{1}{{c}^2 + {d}^2}}}{\frac{1}{a \cdot c + b \cdot d}} \leadsto \frac{\color{blue}{\sqrt[3]{{\left(\frac{1}{{c}^2 + {d}^2}\right)}^3}}}{\frac{1}{a \cdot c + b \cdot d}}\]
      48.1
    9. Applied taylor to get
      \[\frac{\sqrt[3]{{\left(\frac{1}{{c}^2 + {d}^2}\right)}^3}}{\frac{1}{a \cdot c + b \cdot d}} \leadsto \frac{a}{c} + \frac{b \cdot d}{{c}^2}\]
      11.1
    10. Taylor expanded around 0 to get
      \[\color{red}{\frac{a}{c} + \frac{b \cdot d}{{c}^2}} \leadsto \color{blue}{\frac{a}{c} + \frac{b \cdot d}{{c}^2}}\]
      11.1
    11. Applied simplify to get
      \[\frac{a}{c} + \frac{b \cdot d}{{c}^2} \leadsto \frac{a}{c} + \frac{b}{c} \cdot \frac{d}{c}\]
      0.7

    12. Applied final simplification

    if -1.3770151188228676e+30 < c < 1.745403512153814e-141 or 4.1244432764021164e-110 < c < 4.6559433524913966e+129

    1. Started with
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
      18.4

    if 1.745403512153814e-141 < c < 4.1244432764021164e-110

    1. Started with
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
      43.9
    2. Using strategy rm
      43.9
    3. Applied clear-num to get
      \[\color{red}{\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}} \leadsto \color{blue}{\frac{1}{\frac{{c}^2 + {d}^2}{a \cdot c + b \cdot d}}}\]
      44.3
    4. Using strategy rm
      44.3
    5. Applied div-inv to get
      \[\frac{1}{\color{red}{\frac{{c}^2 + {d}^2}{a \cdot c + b \cdot d}}} \leadsto \frac{1}{\color{blue}{\left({c}^2 + {d}^2\right) \cdot \frac{1}{a \cdot c + b \cdot d}}}\]
      44.3
    6. Applied associate-/r* to get
      \[\color{red}{\frac{1}{\left({c}^2 + {d}^2\right) \cdot \frac{1}{a \cdot c + b \cdot d}}} \leadsto \color{blue}{\frac{\frac{1}{{c}^2 + {d}^2}}{\frac{1}{a \cdot c + b \cdot d}}}\]
      43.9
    7. Using strategy rm
      43.9
    8. Applied add-cbrt-cube to get
      \[\frac{\color{red}{\frac{1}{{c}^2 + {d}^2}}}{\frac{1}{a \cdot c + b \cdot d}} \leadsto \frac{\color{blue}{\sqrt[3]{{\left(\frac{1}{{c}^2 + {d}^2}\right)}^3}}}{\frac{1}{a \cdot c + b \cdot d}}\]
      48.2
    9. Applied taylor to get
      \[\frac{\sqrt[3]{{\left(\frac{1}{{c}^2 + {d}^2}\right)}^3}}{\frac{1}{a \cdot c + b \cdot d}} \leadsto \left(\frac{c \cdot a}{{d}^2} + \frac{b}{d}\right) - \frac{b}{{c}^2 \cdot {d}^{3}}\]
      5.8
    10. Taylor expanded around inf to get
      \[\color{red}{\left(\frac{c \cdot a}{{d}^2} + \frac{b}{d}\right) - \frac{b}{{c}^2 \cdot {d}^{3}}} \leadsto \color{blue}{\left(\frac{c \cdot a}{{d}^2} + \frac{b}{d}\right) - \frac{b}{{c}^2 \cdot {d}^{3}}}\]
      5.8
    11. Applied simplify to get
      \[\left(\frac{c \cdot a}{{d}^2} + \frac{b}{d}\right) - \frac{b}{{c}^2 \cdot {d}^{3}} \leadsto \left(\frac{a}{d} \cdot \frac{c}{d} + \frac{b}{d}\right) - \frac{b}{{d}^3 \cdot {c}^2}\]
      5.9

    12. Applied final simplification

  1. Removed slow pow expressions

Original test:


(lambda ((a default) (b default) (c default) (d default))
  #:name "Complex division, real part"
  (/ (+ (* a c) (* b d)) (+ (sqr c) (sqr d)))
  #:target
  (if (< (fabs d) (fabs c)) (/ (+ a (* b (/ d c))) (+ c (* d (/ d c)))) (/ (+ b (* a (/ c d))) (+ d (* c (/ c d))))))