\[\frac{b \cdot c - a \cdot d}{{c}^2 + {d}^2}\]
Test:
Complex division, imag part
Bits:
128 bits
Bits error versus a
Bits error versus b
Bits error versus c
Bits error versus d
Time: 12.6 s
Input Error: 25.4
Output Error: 7.3
Log:
Profile: 🕒
\(\begin{cases} \frac{b \cdot c}{{c}^2 + d \cdot d} - \frac{a}{d + \frac{{c}^2}{d}} & \text{when } d \le -3.2392491068805905 \cdot 10^{+80} \\ \frac{b}{\frac{d \cdot d}{c} + c} - \frac{a \cdot d}{d \cdot d + c \cdot c} & \text{when } d \le 1.0745561433792671 \cdot 10^{+141} \\ -\frac{a}{d} & \text{otherwise} \end{cases}\)

    if d < -3.2392491068805905e+80

    1. Started with
      \[\frac{b \cdot c - a \cdot d}{{c}^2 + {d}^2}\]
      36.5
    2. Using strategy rm
      36.5
    3. Applied div-sub to get
      \[\color{red}{\frac{b \cdot c - a \cdot d}{{c}^2 + {d}^2}} \leadsto \color{blue}{\frac{b \cdot c}{{c}^2 + {d}^2} - \frac{a \cdot d}{{c}^2 + {d}^2}}\]
      36.5
    4. Using strategy rm
      36.5
    5. Applied associate-/l* to get
      \[\frac{b \cdot c}{{c}^2 + {d}^2} - \color{red}{\frac{a \cdot d}{{c}^2 + {d}^2}} \leadsto \frac{b \cdot c}{{c}^2 + {d}^2} - \color{blue}{\frac{a}{\frac{{c}^2 + {d}^2}{d}}}\]
      34.0
    6. Applied taylor to get
      \[\frac{b \cdot c}{{c}^2 + {d}^2} - \frac{a}{\frac{{c}^2 + {d}^2}{d}} \leadsto \frac{b \cdot c}{{c}^2 + {d}^2} - \frac{a}{d + \frac{{c}^2}{d}}\]
      15.9
    7. Taylor expanded around 0 to get
      \[\frac{b \cdot c}{{c}^2 + {d}^2} - \frac{a}{\color{red}{d + \frac{{c}^2}{d}}} \leadsto \frac{b \cdot c}{{c}^2 + {d}^2} - \frac{a}{\color{blue}{d + \frac{{c}^2}{d}}}\]
      15.9
    8. Applied simplify to get
      \[\frac{b \cdot c}{{c}^2 + {d}^2} - \frac{a}{d + \frac{{c}^2}{d}} \leadsto \frac{c \cdot b}{d \cdot d + c \cdot c} - \frac{a}{d + \frac{c}{d} \cdot c}\]
      12.9

    9. Applied final simplification
    10. Applied simplify to get
      \[\color{red}{\frac{c \cdot b}{d \cdot d + c \cdot c} - \frac{a}{d + \frac{c}{d} \cdot c}} \leadsto \color{blue}{\frac{b \cdot c}{{c}^2 + d \cdot d} - \frac{a}{d + \frac{{c}^2}{d}}}\]
      15.9

    if -3.2392491068805905e+80 < d < 1.0745561433792671e+141

    1. Started with
      \[\frac{b \cdot c - a \cdot d}{{c}^2 + {d}^2}\]
      18.4
    2. Using strategy rm
      18.4
    3. Applied div-sub to get
      \[\color{red}{\frac{b \cdot c - a \cdot d}{{c}^2 + {d}^2}} \leadsto \color{blue}{\frac{b \cdot c}{{c}^2 + {d}^2} - \frac{a \cdot d}{{c}^2 + {d}^2}}\]
      18.5
    4. Using strategy rm
      18.5
    5. Applied associate-/l* to get
      \[\color{red}{\frac{b \cdot c}{{c}^2 + {d}^2}} - \frac{a \cdot d}{{c}^2 + {d}^2} \leadsto \color{blue}{\frac{b}{\frac{{c}^2 + {d}^2}{c}}} - \frac{a \cdot d}{{c}^2 + {d}^2}\]
      16.3
    6. Applied taylor to get
      \[\frac{b}{\frac{{c}^2 + {d}^2}{c}} - \frac{a \cdot d}{{c}^2 + {d}^2} \leadsto \frac{b}{c + \frac{{d}^2}{c}} - \frac{a \cdot d}{{c}^2 + {d}^2}\]
      6.4
    7. Taylor expanded around 0 to get
      \[\frac{b}{\color{red}{c + \frac{{d}^2}{c}}} - \frac{a \cdot d}{{c}^2 + {d}^2} \leadsto \frac{b}{\color{blue}{c + \frac{{d}^2}{c}}} - \frac{a \cdot d}{{c}^2 + {d}^2}\]
      6.4
    8. Applied simplify to get
      \[\frac{b}{c + \frac{{d}^2}{c}} - \frac{a \cdot d}{{c}^2 + {d}^2} \leadsto \frac{b}{\frac{d \cdot d}{c} + c} - \frac{a \cdot d}{d \cdot d + c \cdot c}\]
      6.4

    9. Applied final simplification

    if 1.0745561433792671e+141 < d

    1. Started with
      \[\frac{b \cdot c - a \cdot d}{{c}^2 + {d}^2}\]
      41.7
    2. Using strategy rm
      41.7
    3. Applied add-exp-log to get
      \[\frac{b \cdot c - a \cdot d}{\color{red}{{c}^2 + {d}^2}} \leadsto \frac{b \cdot c - a \cdot d}{\color{blue}{e^{\log \left({c}^2 + {d}^2\right)}}}\]
      41.8
    4. Applied add-exp-log to get
      \[\frac{\color{red}{b \cdot c - a \cdot d}}{e^{\log \left({c}^2 + {d}^2\right)}} \leadsto \frac{\color{blue}{e^{\log \left(b \cdot c - a \cdot d\right)}}}{e^{\log \left({c}^2 + {d}^2\right)}}\]
      52.7
    5. Applied div-exp to get
      \[\color{red}{\frac{e^{\log \left(b \cdot c - a \cdot d\right)}}{e^{\log \left({c}^2 + {d}^2\right)}}} \leadsto \color{blue}{e^{\log \left(b \cdot c - a \cdot d\right) - \log \left({c}^2 + {d}^2\right)}}\]
      52.7
    6. Applied taylor to get
      \[e^{\log \left(b \cdot c - a \cdot d\right) - \log \left({c}^2 + {d}^2\right)} \leadsto e^{\left(\log a + \log -1\right) - \log d}\]
      62.9
    7. Taylor expanded around 0 to get
      \[\color{red}{e^{\left(\log a + \log -1\right) - \log d}} \leadsto \color{blue}{e^{\left(\log a + \log -1\right) - \log d}}\]
      62.9
    8. Applied simplify to get
      \[e^{\left(\log a + \log -1\right) - \log d} \leadsto \frac{-1}{d} \cdot a\]
      0.2

    9. Applied final simplification
    10. Applied simplify to get
      \[\color{red}{\frac{-1}{d} \cdot a} \leadsto \color{blue}{-\frac{a}{d}}\]
      0

  1. Removed slow pow expressions

Original test:


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