El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\left(- \sin{\left(x \right)} - \cos{\left(x \right)}\right) e^{- x} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{\pi}{4}$$
Solución numérica$$x_{1} = 21.2057504117311$$
$$x_{2} = 68.329640215578$$
$$x_{3} = 84.037603483527$$
$$x_{4} = 62.0464549083984$$
$$x_{5} = 8.63937979737193$$
$$x_{6} = 74.6128255227576$$
$$x_{7} = -10.2101761241668$$
$$x_{8} = 58.9048622548086$$
$$x_{9} = 5.49778714378214$$
$$x_{10} = 80.8960108299372$$
$$x_{11} = -0.785398163397448$$
$$x_{12} = 18.0641577581413$$
$$x_{13} = 93.4623814442964$$
$$x_{14} = -13.3517687777566$$
$$x_{15} = 55.7632696012188$$
$$x_{16} = 46.3384916404494$$
$$x_{17} = 40.0553063332699$$
$$x_{18} = 33.7721210260903$$
$$x_{19} = -16.4933614313464$$
$$x_{20} = 11.7809724509617$$
$$x_{21} = 49.4800842940392$$
$$x_{22} = 65.1880475619882$$
$$x_{23} = 71.4712328691678$$
$$x_{24} = 96.6039740978861$$
$$x_{25} = -29.0597320457056$$
$$x_{26} = -22.776546738526$$
$$x_{27} = 52.621676947629$$
$$x_{28} = -25.9181393921158$$
$$x_{29} = 36.9137136796801$$
$$x_{30} = 30.6305283725005$$
$$x_{31} = 14.9225651045515$$
$$x_{32} = -19.6349540849362$$
$$x_{33} = 99.7455667514759$$
$$x_{34} = 2.35619449019234$$
$$x_{35} = 87.1791961371168$$
$$x_{36} = -3.92699081698724$$
$$x_{37} = 90.3207887907066$$
$$x_{38} = 43.1968989868597$$
$$x_{39} = 77.7544181763474$$
$$x_{40} = 27.4889357189107$$
$$x_{41} = -7.06858347057703$$
$$x_{42} = 24.3473430653209$$