\[\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)}\]

\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)}

double f(double t, double l, double k) {
        double r57189070 = 2.0;
        double r57189071 = t;
        double r57189072 = 3.0;
        double r57189073 = pow(r57189071, r57189072);
        double r57189074 = l;
        double r57189075 = r57189074 * r57189074;
        double r57189076 = r57189073 / r57189075;
        double r57189077 = k;
        double r57189078 = sin(r57189077);
        double r57189079 = r57189076 * r57189078;
        double r57189080 = tan(r57189077);
        double r57189081 = r57189079 * r57189080;
        double r57189082 = 1.0;
        double r57189083 = r57189077 / r57189071;
        double r57189084 = pow(r57189083, r57189070);
        double r57189085 = r57189082 + r57189084;
        double r57189086 = r57189085 + r57189082;
        double r57189087 = r57189081 * r57189086;
        double r57189088 = r57189070 / r57189087;
        return r57189088;
}

Reproduce

herbie shell --seed 2019120 +o rules:numerics
(FPCore (t l k)
  :name "Toniolo and Linder, Equation (10+)"
  (/ 2 (* (* (* (/ (pow t 3) (* l l)) (sin k)) (tan k)) (+ (+ 1 (pow (/ k t) 2)) 1))))

Timeout in 10.0m

Reproduce