Average Error: 18.0 → 17.3
Time: 21.1s
Precision: binary64
Cost: 28806
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}}\]
\[\begin{array}{l} \mathbf{if}\;J \leq -2.1144643127566853 \cdot 10^{-111}:\\ \;\;\;\;\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot -2\right)\right)\\ \mathbf{elif}\;J \leq -3.407987670226901 \cdot 10^{-287}:\\ \;\;\;\;U\\ \mathbf{elif}\;J \leq 5.129303200657122 \cdot 10^{-263}:\\ \;\;\;\;-2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U} - U\\ \mathbf{elif}\;J \leq 1.2804491241499647 \cdot 10^{-217}:\\ \;\;\;\;U + 2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U}\\ \mathbf{elif}\;J \leq 8.15590711171135 \cdot 10^{-182}:\\ \;\;\;\;\left(J \cdot -2\right) \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}\right)\\ \mathbf{elif}\;J \leq 3.5351986706589427 \cdot 10^{-112}:\\ \;\;\;\;U\\ \mathbf{else}:\\ \;\;\;\;\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot -2\right)\right)\\ \end{array}\]
\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}}
\begin{array}{l}
\mathbf{if}\;J \leq -2.1144643127566853 \cdot 10^{-111}:\\
\;\;\;\;\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot -2\right)\right)\\

\mathbf{elif}\;J \leq -3.407987670226901 \cdot 10^{-287}:\\
\;\;\;\;U\\

\mathbf{elif}\;J \leq 5.129303200657122 \cdot 10^{-263}:\\
\;\;\;\;-2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U} - U\\

\mathbf{elif}\;J \leq 1.2804491241499647 \cdot 10^{-217}:\\
\;\;\;\;U + 2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U}\\

\mathbf{elif}\;J \leq 8.15590711171135 \cdot 10^{-182}:\\
\;\;\;\;\left(J \cdot -2\right) \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}\right)\\

\mathbf{elif}\;J \leq 3.5351986706589427 \cdot 10^{-112}:\\
\;\;\;\;U\\

\mathbf{else}:\\
\;\;\;\;\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot -2\right)\right)\\

\end{array}
(FPCore (J K U)
 :precision binary64
 (*
  (* (* -2.0 J) (cos (/ K 2.0)))
  (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) (cos (/ K 2.0)))) 2.0)))))
(FPCore (J K U)
 :precision binary64
 (if (<= J -2.1144643127566853e-111)
   (*
    (sqrt (+ 1.0 (pow (/ U (* (cos (/ K 2.0)) (* J 2.0))) 2.0)))
    (* (cos (/ K 2.0)) (* J -2.0)))
   (if (<= J -3.407987670226901e-287)
     U
     (if (<= J 5.129303200657122e-263)
       (- (* -2.0 (/ (* (* J J) (pow (cos (* K 0.5)) 2.0)) U)) U)
       (if (<= J 1.2804491241499647e-217)
         (+ U (* 2.0 (/ (* (* J J) (pow (cos (* K 0.5)) 2.0)) U)))
         (if (<= J 8.15590711171135e-182)
           (*
            (* J -2.0)
            (*
             (cos (/ K 2.0))
             (sqrt (+ 1.0 (pow (/ U (* (cos (/ K 2.0)) (* J 2.0))) 2.0)))))
           (if (<= J 3.5351986706589427e-112)
             U
             (*
              (sqrt (+ 1.0 (pow (/ U (* (cos (/ K 2.0)) (* J 2.0))) 2.0)))
              (* (cos (/ K 2.0)) (* J -2.0))))))))))
double code(double J, double K, double U) {
	return ((-2.0 * J) * cos(K / 2.0)) * sqrt(1.0 + pow((U / ((2.0 * J) * cos(K / 2.0))), 2.0));
}
double code(double J, double K, double U) {
	double tmp;
	if (J <= -2.1144643127566853e-111) {
		tmp = sqrt(1.0 + pow((U / (cos(K / 2.0) * (J * 2.0))), 2.0)) * (cos(K / 2.0) * (J * -2.0));
	} else if (J <= -3.407987670226901e-287) {
		tmp = U;
	} else if (J <= 5.129303200657122e-263) {
		tmp = (-2.0 * (((J * J) * pow(cos(K * 0.5), 2.0)) / U)) - U;
	} else if (J <= 1.2804491241499647e-217) {
		tmp = U + (2.0 * (((J * J) * pow(cos(K * 0.5), 2.0)) / U));
	} else if (J <= 8.15590711171135e-182) {
		tmp = (J * -2.0) * (cos(K / 2.0) * sqrt(1.0 + pow((U / (cos(K / 2.0) * (J * 2.0))), 2.0)));
	} else if (J <= 3.5351986706589427e-112) {
		tmp = U;
	} else {
		tmp = sqrt(1.0 + pow((U / (cos(K / 2.0) * (J * 2.0))), 2.0)) * (cos(K / 2.0) * (J * -2.0));
	}
	return tmp;
}

Error

Bits error versus J

Bits error versus K

Bits error versus U

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Alternatives

Alternative 1
Error18.9
Cost99968
\[\sqrt[3]{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)} \cdot \left(\sqrt[3]{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)} \cdot \sqrt[3]{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)}\right)\]
Alternative 2
Error18.4
Cost72192
\[\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(\left(-2 \cdot J\right) \cdot \left(\sqrt[3]{\cos \left(\frac{K}{2}\right)} \cdot \sqrt[3]{\cos \left(\frac{K}{2}\right)}\right)\right) \cdot \log \left(e^{\sqrt[3]{\cos \left(\frac{K}{2}\right)}}\right)\right)\]
Alternative 3
Error41.3
Cost66624
\[\sqrt{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)} \cdot \sqrt{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)}\]
Alternative 4
Error18.9
Cost59904
\[\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\sqrt[3]{\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)} \cdot \left(\sqrt[3]{\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)} \cdot \sqrt[3]{\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)\right)\]
Alternative 5
Error18.1
Cost59712
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \left(\sqrt{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}} \cdot \sqrt{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}}\right)\]
Alternative 6
Error18.1
Cost59712
\[\left(\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \left|\sqrt[3]{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}\right|\right) \cdot \sqrt{\sqrt[3]{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}}\]
Alternative 7
Error18.1
Cost59712
\[\sqrt{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}} \cdot \left(\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}}\right)\]
Alternative 8
Error29.5
Cost59456
\[\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(\left(-2 \cdot J\right) \cdot \left(\sqrt[3]{\cos \left(\frac{K}{2}\right)} \cdot \sqrt[3]{\cos \left(\frac{K}{2}\right)}\right)\right) \cdot {\cos \left(\frac{K}{2}\right)}^{0.3333333333333333}\right)\]
Alternative 9
Error18.4
Cost59392
\[\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\sqrt[3]{\cos \left(\frac{K}{2}\right)} \cdot \left(\left(-2 \cdot J\right) \cdot \left(\sqrt[3]{\cos \left(\frac{K}{2}\right)} \cdot \sqrt[3]{\cos \left(\frac{K}{2}\right)}\right)\right)\right)\]
Alternative 10
Error31.2
Cost52160
\[\left(\left(-2 \cdot J\right) \cdot \left(\sqrt[3]{\cos \left(\frac{K}{2}\right)} \cdot \sqrt[3]{\cos \left(\frac{K}{2}\right)}\right)\right) \cdot \log \left(e^{\sqrt[3]{\cos \left(\frac{K}{2}\right)}}\right)\]
Alternative 11
Error41.3
Cost46592
\[\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\sqrt{\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)} \cdot \sqrt{\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)\]
Alternative 12
Error47.8
Cost39744
\[\sqrt[3]{{\left(\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)\right)}^{3}}\]
Alternative 13
Error47.8
Cost39744
\[\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \sqrt[3]{{\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)}^{3}}\]
Alternative 14
Error31.2
Cost39360
\[\sqrt[3]{\cos \left(\frac{K}{2}\right)} \cdot \left(\left(-2 \cdot J\right) \cdot \left(\sqrt[3]{\cos \left(\frac{K}{2}\right)} \cdot \sqrt[3]{\cos \left(\frac{K}{2}\right)}\right)\right)\]
Alternative 15
Error30.0
Cost33344
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{0.5}{J}\right)}^{2} \cdot {\left(\frac{U}{\cos \left(\frac{K}{2}\right)}\right)}^{2}}\]
Alternative 16
Error30.0
Cost27008
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + \left(U \cdot U\right) \cdot {\left(\frac{\frac{0.5}{J}}{\cos \left(\frac{K}{2}\right)}\right)}^{2}}\]
Alternative 17
Error18.0
Cost26880
\[\left(-2 \cdot J\right) \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}\right)\]
Alternative 18
Error18.0
Cost26880
\[\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)\]
Alternative 19
Error50.9
Cost20800
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \left(\frac{U}{J \cdot \cos \left(K \cdot 0.5\right)} \cdot -0.5 - \frac{J \cdot \cos \left(K \cdot 0.5\right)}{U}\right)\]
Alternative 20
Error51.6
Cost20800
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \left(\frac{J \cdot \cos \left(K \cdot 0.5\right)}{U} + 0.5 \cdot \frac{U}{J \cdot \cos \left(K \cdot 0.5\right)}\right)\]
Alternative 21
Error38.8
Cost20224
\[\left(-2 \cdot J\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}\]
Alternative 22
Error31.2
Cost14016
\[-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right) - 0.25 \cdot \left(U \cdot \frac{U}{J \cdot \cos \left(K \cdot 0.5\right)}\right)\]
Alternative 23
Error32.3
Cost14016
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + 0.25 \cdot \frac{U \cdot U}{J \cdot J}}\]
Alternative 24
Error50.5
Cost13888
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \left(\frac{U}{J \cdot \cos \left(K \cdot 0.5\right)} \cdot -0.5\right)\]
Alternative 25
Error51.2
Cost13888
\[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \left(0.5 \cdot \frac{U}{J \cdot \cos \left(K \cdot 0.5\right)}\right)\]
Alternative 26
Error48.0
Cost13696
\[U + 2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U}\]
Alternative 27
Error48.7
Cost13696
\[-2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U} - U\]
Alternative 28
Error44.3
Cost7360
\[-2 \cdot \left(J \cdot \sqrt{1 + 0.25 \cdot \frac{U \cdot U}{J \cdot J}}\right)\]
Alternative 29
Error30.9
Cost6848
\[-2 \cdot \left(J \cdot \cos \left(K \cdot 0.5\right)\right)\]
Alternative 30
Error30.9
Cost6848
\[\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\]
Alternative 31
Error47.2
Cost128
\[-U\]
Alternative 32
Error46.5
Cost64
\[U\]
Alternative 33
Error61.9
Cost64
\[1\]
Alternative 34
Error62.3
Cost64
\[0\]
Alternative 35
Error61.9
Cost64
\[-1\]

Error

Derivation

  1. Split input into 5 regimes
  2. if J < -2.1144643127566853e-111 or 3.53519867065894268e-112 < J

    1. Initial program 8.7

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}}\]
    2. Simplified8.7

      \[\leadsto \color{blue}{\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right)}\]

    if -2.1144643127566853e-111 < J < -3.407987670226901e-287 or 8.15590711171135e-182 < J < 3.53519867065894268e-112

    1. Initial program 35.3

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}}\]
    2. Taylor expanded around -inf 36.7

      \[\leadsto \color{blue}{U}\]
    3. Simplified36.7

      \[\leadsto \color{blue}{U}\]

    if -3.407987670226901e-287 < J < 5.1293032006571219e-263

    1. Initial program 45.9

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}}\]
    2. Taylor expanded around 0 32.0

      \[\leadsto \color{blue}{-\left(2 \cdot \frac{{\cos \left(0.5 \cdot K\right)}^{2} \cdot {J}^{2}}{U} + U\right)}\]
    3. Simplified32.0

      \[\leadsto \color{blue}{-2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U} - U}\]
    4. Simplified32.0

      \[\leadsto \color{blue}{-2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U} - U}\]

    if 5.1293032006571219e-263 < J < 1.2804491241499647e-217

    1. Initial program 39.8

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}}\]
    2. Taylor expanded around -inf 34.4

      \[\leadsto \color{blue}{2 \cdot \frac{{\cos \left(0.5 \cdot K\right)}^{2} \cdot {J}^{2}}{U} + U}\]
    3. Simplified34.4

      \[\leadsto \color{blue}{U + 2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U}}\]
    4. Simplified34.4

      \[\leadsto \color{blue}{U + 2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U}}\]

    if 1.2804491241499647e-217 < J < 8.15590711171135e-182

    1. Initial program 36.0

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}}\]
    2. Using strategy rm
    3. Applied associate-*l*_binary64_101136.0

      \[\leadsto \color{blue}{\left(-2 \cdot J\right) \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}}\right)}\]
    4. Simplified36.0

      \[\leadsto \color{blue}{\left(-2 \cdot J\right) \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}\right)}\]
  3. Recombined 5 regimes into one program.
  4. Final simplification17.3

    \[\leadsto \begin{array}{l} \mathbf{if}\;J \leq -2.1144643127566853 \cdot 10^{-111}:\\ \;\;\;\;\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot -2\right)\right)\\ \mathbf{elif}\;J \leq -3.407987670226901 \cdot 10^{-287}:\\ \;\;\;\;U\\ \mathbf{elif}\;J \leq 5.129303200657122 \cdot 10^{-263}:\\ \;\;\;\;-2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U} - U\\ \mathbf{elif}\;J \leq 1.2804491241499647 \cdot 10^{-217}:\\ \;\;\;\;U + 2 \cdot \frac{\left(J \cdot J\right) \cdot {\cos \left(K \cdot 0.5\right)}^{2}}{U}\\ \mathbf{elif}\;J \leq 8.15590711171135 \cdot 10^{-182}:\\ \;\;\;\;\left(J \cdot -2\right) \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}}\right)\\ \mathbf{elif}\;J \leq 3.5351986706589427 \cdot 10^{-112}:\\ \;\;\;\;U\\ \mathbf{else}:\\ \;\;\;\;\sqrt{1 + {\left(\frac{U}{\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot 2\right)}\right)}^{2}} \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J \cdot -2\right)\right)\\ \end{array}\]

Reproduce

herbie shell --seed 2021042 
(FPCore (J K U)
  :name "Maksimov and Kolovsky, Equation (3)"
  :precision binary64
  (* (* (* -2.0 J) (cos (/ K 2.0))) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) (cos (/ K 2.0)))) 2.0)))))