El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\left(\sqrt{\sin{\left(x \right)} + \cos{\left(x \right)}}\right)^{2} - 1 = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 0$$
$$x_{2} = \frac{\pi}{2}$$
Solución numérica$$x_{1} = -98.9601685880785$$
$$x_{2} = 76.9690200129499$$
$$x_{3} = 81.6814089933346$$
$$x_{4} = -43.9822971502571$$
$$x_{5} = -100.530964914873$$
$$x_{6} = 58.1194640914112$$
$$x_{7} = 14.1371669411541$$
$$x_{8} = -29.845130209103$$
$$x_{9} = -36.1283155162826$$
$$x_{10} = -4.71238898038469$$
$$x_{11} = 1.5707963267949$$
$$x_{12} = -31.4159265358979$$
$$x_{13} = 56.5486677646163$$
$$x_{14} = -67.5442420521806$$
$$x_{15} = -56.5486677646163$$
$$x_{16} = 12.5663706143592$$
$$x_{17} = 43.9822971502571$$
$$x_{18} = -86.3937979737193$$
$$x_{19} = 100.530964914873$$
$$x_{20} = 39.2699081698724$$
$$x_{21} = 7.85398163397448$$
$$x_{22} = 6.28318530717959$$
$$x_{23} = -61.261056745001$$
$$x_{24} = -87.9645943005142$$
$$x_{25} = -73.8274273593601$$
$$x_{26} = 87.9645943005142$$
$$x_{27} = 18.8495559215388$$
$$x_{28} = 69.1150383789755$$
$$x_{29} = 25.1327412287183$$
$$x_{30} = -25.1327412287183$$
$$x_{31} = 37.6991118430775$$
$$x_{32} = 0$$
$$x_{33} = 50.2654824574367$$
$$x_{34} = -6.28318530717959$$
$$x_{35} = 89.5353906273091$$
$$x_{36} = 64.4026493985908$$
$$x_{37} = -62.8318530717959$$
$$x_{38} = 75.398223686155$$
$$x_{39} = 51.8362787842316$$
$$x_{40} = 83.2522053201295$$
$$x_{41} = 150.79644737231$$
$$x_{42} = -48.6946861306418$$
$$x_{43} = -54.9778714378214$$
$$x_{44} = -69.1150383789755$$
$$x_{45} = 70.6858347057703$$
$$x_{46} = 94.2477796076938$$
$$x_{47} = -18.8495559215388$$
$$x_{48} = 26.7035375555132$$
$$x_{49} = -50.2654824574367$$
$$x_{50} = -37.6991118430775$$
$$x_{51} = -23.5619449019235$$
$$x_{52} = -81.6814089933346$$
$$x_{53} = 62.8318530717959$$
$$x_{54} = -42.4115008234622$$
$$x_{55} = 31.4159265358979$$
$$x_{56} = 32.9867228626928$$
$$x_{57} = 119.380520836412$$
$$x_{58} = 20.4203522483337$$
$$x_{59} = -1217.36715326604$$
$$x_{60} = -10.9955742875643$$
$$x_{61} = -92.6769832808989$$
$$x_{62} = -75.398223686155$$
$$x_{63} = 45.553093477052$$
$$x_{64} = -17.2787595947439$$
$$x_{65} = -12.5663706143592$$
$$x_{66} = -80.1106126665397$$
$$x_{67} = -94.2477796076938$$
$$x_{68} = 95.8185759344887$$