\[\frac{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}\]
Test:
NMSE p42, positive
Bits:
128 bits
Bits error versus a
Bits error versus b
Bits error versus c
Time: 1.4 m
Input Error: 37.1
Output Error: 5.2
Log:
Profile: 🕒
\(\begin{cases} \frac{\frac{c}{b}}{1} - \frac{b}{a} & \text{when } b \le -2.2913476789857995 \cdot 10^{+35} \\ \frac{\left(-\sqrt{{b}^2 - a \cdot \left(4 \cdot c\right)}\right) + b}{-2 \cdot a} & \text{when } b \le 2.890760014197913 \cdot 10^{-73} \\ \frac{c}{-b} & \text{otherwise} \end{cases}\)

    if b < -2.2913476789857995e+35

    1. Started with
      \[\frac{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}\]
      38.0
    2. Using strategy rm
      38.0
    3. Applied clear-num to get
      \[\color{red}{\frac{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}} \leadsto \color{blue}{\frac{1}{\frac{2 \cdot a}{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}}}\]
      38.1
    4. Applied taylor to get
      \[\frac{1}{\frac{2 \cdot a}{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}} \leadsto \frac{1}{\frac{2 \cdot a}{2 \cdot \frac{c \cdot a}{b} - 2 \cdot b}}\]
      10.6
    5. Taylor expanded around -inf to get
      \[\frac{1}{\frac{2 \cdot a}{\color{red}{2 \cdot \frac{c \cdot a}{b} - 2 \cdot b}}} \leadsto \frac{1}{\frac{2 \cdot a}{\color{blue}{2 \cdot \frac{c \cdot a}{b} - 2 \cdot b}}}\]
      10.6
    6. Applied simplify to get
      \[\frac{1}{\frac{2 \cdot a}{2 \cdot \frac{c \cdot a}{b} - 2 \cdot b}} \leadsto \frac{1}{\frac{\frac{a}{1}}{a \cdot \frac{c}{b} - b}}\]
      3.1

    7. Applied final simplification
    8. Applied simplify to get
      \[\color{red}{\frac{1}{\frac{\frac{a}{1}}{a \cdot \frac{c}{b} - b}}} \leadsto \color{blue}{\frac{\frac{c}{b}}{1} - \frac{b}{a}}\]
      0.0

    if -2.2913476789857995e+35 < b < 2.890760014197913e-73

    1. Started with
      \[\frac{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}\]
      13.8
    2. Using strategy rm
      13.8
    3. Applied frac-2neg to get
      \[\color{red}{\frac{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}} \leadsto \color{blue}{\frac{-\left(\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}\right)}{-2 \cdot a}}\]
      13.8
    4. Applied simplify to get
      \[\frac{\color{red}{-\left(\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}\right)}}{-2 \cdot a} \leadsto \frac{\color{blue}{\left(-\sqrt{{b}^2 - a \cdot \left(4 \cdot c\right)}\right) + b}}{-2 \cdot a}\]
      13.9

    if 2.890760014197913e-73 < b

    1. Started with
      \[\frac{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}\]
      58.3
    2. Using strategy rm
      58.3
    3. Applied clear-num to get
      \[\color{red}{\frac{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}} \leadsto \color{blue}{\frac{1}{\frac{2 \cdot a}{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}}}\]
      58.3
    4. Applied taylor to get
      \[\frac{1}{\frac{2 \cdot a}{\left(-b\right) + \sqrt{{b}^2 - 4 \cdot \left(a \cdot c\right)}}} \leadsto \frac{1}{-1 \cdot \frac{b}{c}}\]
      0.7
    5. Taylor expanded around 0 to get
      \[\frac{1}{\color{red}{-1 \cdot \frac{b}{c}}} \leadsto \frac{1}{\color{blue}{-1 \cdot \frac{b}{c}}}\]
      0.7
    6. Applied simplify to get
      \[\frac{1}{-1 \cdot \frac{b}{c}} \leadsto \frac{\frac{1}{-1}}{\frac{b}{c}}\]
      0.7

    7. Applied final simplification
    8. Applied simplify to get
      \[\color{red}{\frac{\frac{1}{-1}}{\frac{b}{c}}} \leadsto \color{blue}{\frac{c}{-b}}\]
      0

  1. Removed slow pow expressions

Original test:


(lambda ((a default) (b default) (c default))
  #:name "NMSE p42, positive"
  (/ (+ (- b) (sqrt (- (sqr b) (* 4 (* a c))))) (* 2 a))
  #:target
  (if (< b 0) (/ (+ (- b) (sqrt (- (sqr b) (* 4 (* a c))))) (* 2 a)) (/ c (* a (/ (- (- b) (sqrt (- (sqr b) (* 4 (* a c))))) (* 2 a))))))