El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\left(\sin{\left(x \right)} + \cos{\left(x \right)}\right)^{2} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{\pi}{4}$$
$$x_{2} = \frac{3 \pi}{4}$$
Solución numérica$$x_{1} = -85.608399894653$$
$$x_{2} = -29.0597320982225$$
$$x_{3} = 62.0464548195549$$
$$x_{4} = -44.7676954314418$$
$$x_{5} = -3.92699107594367$$
$$x_{6} = 43.1968992294597$$
$$x_{7} = 14.9225648553046$$
$$x_{8} = -41.6261027352652$$
$$x_{9} = 21.2057502602382$$
$$x_{10} = 36.9137135281996$$
$$x_{11} = -60.4756585174615$$
$$x_{12} = 49.4800845342934$$
$$x_{13} = -44.7676950635734$$
$$x_{14} = -63.6172513149926$$
$$x_{15} = -0.785398304611266$$
$$x_{16} = 24.3473430043575$$
$$x_{17} = -73.0420294459387$$
$$x_{18} = -7.06858355298869$$
$$x_{19} = 40.0553062099627$$
$$x_{20} = 71.471233111112$$
$$x_{21} = -54.1924731445711$$
$$x_{22} = 99.7455669089878$$
$$x_{23} = 11.7809725930891$$
$$x_{24} = -66.7588439932285$$
$$x_{25} = 52.6216767646073$$
$$x_{26} = 14.9225649892472$$
$$x_{27} = -35.3429175479242$$
$$x_{28} = -51.0508806461775$$
$$x_{29} = 84.0376034199549$$
$$x_{30} = 58.9048620066655$$
$$x_{31} = 36.9137134309271$$
$$x_{32} = -82.4668069282144$$
$$x_{33} = -38.4845103583538$$
$$x_{34} = 18.0641575837788$$
$$x_{35} = -73.0420291965934$$
$$x_{36} = -60.4756583509459$$
$$x_{37} = -16.4933611966261$$
$$x_{38} = 87.1791963746667$$
$$x_{39} = 96.6039739212089$$
$$x_{40} = -76.1836225361187$$
$$x_{41} = 55.7632697006301$$
$$x_{42} = -0.785397916651749$$
$$x_{43} = 80.896010582516$$
$$x_{44} = -32.2013245652766$$
$$x_{45} = -35.3429178934093$$
$$x_{46} = 77.7544183301131$$
$$x_{47} = -51.0508808708243$$
$$x_{48} = -22.7765464900166$$
$$x_{49} = -38.4845097737495$$
$$x_{50} = 62.0464547256144$$
$$x_{51} = -7.0685837201977$$
$$x_{52} = -79.3252147038408$$
$$x_{53} = -95.0331780209134$$
$$x_{54} = -13.3517689698773$$
$$x_{55} = 65.1880478021829$$
$$x_{56} = 68.3296401645238$$
$$x_{57} = 65.1880473923958$$
$$x_{58} = -22.7765468685351$$
$$x_{59} = -57.3340661259123$$
$$x_{60} = 74.6128253428807$$
$$x_{61} = -98.1747703033985$$
$$x_{62} = 27.4889359573966$$
$$x_{63} = 90.3207887447523$$
$$x_{64} = 87.1791959595656$$
$$x_{65} = 21.2057506565108$$
$$x_{66} = 55.7632697511726$$
$$x_{67} = 43.1968988259316$$
$$x_{68} = -88.7499922112266$$
$$x_{69} = 80.8960105951638$$
$$x_{70} = -29.0597322955756$$
$$x_{71} = 58.9048620635881$$
$$x_{72} = -101.316363786262$$
$$x_{73} = 33.7721211721652$$
$$x_{74} = 2.35619442440536$$
$$x_{75} = 5.49778738042301$$
$$x_{76} = 8.63937960822746$$
$$x_{77} = -88.7499925537801$$
$$x_{78} = -91.8915845717239$$
$$x_{79} = 93.462381687851$$
$$x_{80} = -76.1836217239439$$
$$x_{81} = -10.2101759860574$$
$$x_{82} = 96.6039739773235$$
$$x_{83} = 46.3384915843947$$
$$x_{84} = -66.758843637313$$
$$x_{85} = -19.6349541554673$$
$$x_{86} = -95.0331777492301$$
$$x_{87} = 30.6305281863893$$