El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\cos{\left(\sqrt{x} \right)} - 1 = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 0$$
$$x_{2} = 4 \pi^{2}$$
Solución numérica$$x_{1} = 39.4784150350481$$
$$x_{2} = 39.4784098692181$$
$$x_{3} = 157.913697463567$$
$$x_{4} = 39.4784169919817$$
$$x_{5} = 39.4784130487571$$
$$x_{6} = 39.4784231008965$$
$$x_{7} = 39.4784203522095$$
$$x_{8} = 39.4784230848873$$
$$x_{9} = 39.4784213050027$$
$$x_{10} = 39.4784104527582$$
$$x_{11} = 39.4784110714148$$
$$x_{12} = 0$$
$$x_{13} = 39.4784316363598$$
$$x_{14} = 39.4784187848578$$
$$x_{15} = 39.4784120981909$$
$$x_{16} = 631.654699417355$$
$$x_{17} = 39.4784231686652$$
$$x_{18} = 39.478416025174$$
$$x_{19} = 39.4784222927795$$
$$x_{20} = 39.4784196022413$$
$$x_{21} = 39.4784112177865$$
$$x_{22} = 39.4784221363365$$
$$x_{23} = 39.4784228366928$$
$$x_{24} = 157.913682331179$$
$$x_{25} = 39.4784094124511$$
$$x_{26} = 39.4784228752785$$
$$x_{27} = 39.47841790122$$
$$x_{28} = 39.4784195276429$$
$$x_{29} = 39.4784225556012$$
$$x_{30} = 39.4784216251889$$
$$x_{31} = 39.4784095759701$$
$$x_{32} = 39.4784161776161$$
$$x_{33} = 39.4784155555891$$
$$x_{34} = 39.478414036228$$
$$x_{35} = 39.4783993417375$$
$$x_{36} = 39.4784097888015$$
$$x_{37} = 39.4784210285171$$