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$$x_{1} = \pi^{2}$$
Solución numérica$$x_{1} = 88.8264288008564$$
$$x_{2} = 88.8264285616228$$
$$x_{3} = 9.86960686816032$$
$$x_{4} = 9.86960640630053$$
$$x_{5} = 88.8264319233893$$
$$x_{6} = 88.8264398542051$$
$$x_{7} = 9.86960596066849$$
$$x_{8} = 88.8264311258122$$
$$x_{9} = 88.8264374232545$$
$$x_{10} = 88.8264411026587$$
$$x_{11} = 9.86960532951284$$
$$x_{12} = 9.86960531292722$$
$$x_{13} = 88.8264364719572$$
$$x_{14} = 88.8264435755279$$
$$x_{15} = 88.8264340104362$$
$$x_{16} = 88.8264355228443$$
$$x_{17} = 88.8264419636407$$
$$x_{18} = 9.86959526897085$$
$$x_{19} = 9.86959743483978$$
$$x_{20} = 9.8696035483378$$
$$x_{21} = 9.86960236123105$$
$$x_{22} = 88.8264443177415$$
$$x_{23} = 88.8264345839786$$
$$x_{24} = 88.8264393095436$$
$$x_{25} = 9.86960189451837$$
$$x_{26} = 88.8264311002467$$
$$x_{27} = 88.8264285451447$$
$$x_{28} = 88.8264297495879$$
$$x_{29} = 88.8264383696962$$
$$x_{30} = 88.8264327737412$$
$$x_{31} = 88.8264295903598$$
$$x_{32} = 88.8264521106931$$
$$x_{33} = 88.8264288374812$$
$$x_{34} = 88.8264292090665$$
$$x_{35} = 88.8264214194504$$
$$x_{36} = 9.86960450077527$$
$$x_{37} = 9.86960679732024$$
$$x_{38} = 9.86960095981624$$
$$x_{39} = 9.86960642730761$$
$$x_{40} = 88.826442789391$$
$$x_{41} = 9.86959932448707$$
$$x_{42} = 9.86960673273734$$
$$x_{43} = 88.8264402093905$$
$$x_{44} = 88.826430395499$$
$$x_{45} = 88.826433664303$$