El gráfico de la función cruce el eje T con f = 0
o sea hay que resolver la ecuación:
$$\cos{\left(t \right)} + 1 = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje T:
Solución analítica$$t_{1} = \pi$$
Solución numérica$$t_{1} = -84.8230012511693$$
$$t_{2} = 47.1238902162437$$
$$t_{3} = 97.389372581711$$
$$t_{4} = -91.1061864815274$$
$$t_{5} = -40.8407049008781$$
$$t_{6} = 65.9734457529812$$
$$t_{7} = -65.9734449870253$$
$$t_{8} = -47.1238893275319$$
$$t_{9} = -59.6902599212271$$
$$t_{10} = 59.6902599104079$$
$$t_{11} = -47.1238901083229$$
$$t_{12} = 40.8407049800347$$
$$t_{13} = -15.7079635641079$$
$$t_{14} = -59.6902604578012$$
$$t_{15} = 47.123889410773$$
$$t_{16} = -34.5575188899093$$
$$t_{17} = 72.2566315166773$$
$$t_{18} = 84.8230013636028$$
$$t_{19} = -97.3893716284562$$
$$t_{20} = 34.5575195449229$$
$$t_{21} = -21.991148226056$$
$$t_{22} = -40.8407040952604$$
$$t_{23} = 40.8407045792514$$
$$t_{24} = 28.2743343711514$$
$$t_{25} = 91.1061865667532$$
$$t_{26} = -40.8407049290801$$
$$t_{27} = -65.9734461969855$$
$$t_{28} = -97.3893724533348$$
$$t_{29} = 78.5398161804942$$
$$t_{30} = 28.2743338651796$$
$$t_{31} = -53.407075294995$$
$$t_{32} = -9.42477752082051$$
$$t_{33} = 21.9911489072506$$
$$t_{34} = -84.8230020565447$$
$$t_{35} = -1127.83176318906$$
$$t_{36} = -78.5398160472843$$
$$t_{37} = 15.7079627593774$$
$$t_{38} = -3.14159217367683$$
$$t_{39} = 34.5575197055812$$
$$t_{40} = -21.9911485864417$$
$$t_{41} = 21.9911480932338$$
$$t_{42} = 91.1061873718352$$
$$t_{43} = -3.14159295109225$$
$$t_{44} = -15.707962774825$$
$$t_{45} = 78.5398152766482$$
$$t_{46} = 15.7079634518075$$
$$t_{47} = 15.7079629803241$$
$$t_{48} = 21.9911485852059$$
$$t_{49} = -65.9734457649277$$
$$t_{50} = 9.42477748794163$$
$$t_{51} = -9.4247781365785$$
$$t_{52} = -72.2566315419804$$
$$t_{53} = 59.6902606104322$$
$$t_{54} = 72.2566310277176$$
$$t_{55} = -91.106187265474$$
$$t_{56} = -65.9734453607004$$
$$t_{57} = 59.6902600526626$$
$$t_{58} = 97.3893717959212$$
$$t_{59} = -21.9911490521325$$
$$t_{60} = -34.5575196658297$$
$$t_{61} = -28.2743340989896$$
$$t_{62} = -53.4070745963886$$
$$t_{63} = 78.5398166181283$$
$$t_{64} = 53.407075424589$$
$$t_{65} = -72.2566308657983$$
$$t_{66} = -53.4070745786761$$
$$t_{67} = 40.8407045848602$$
$$t_{68} = 9.42477826738203$$
$$t_{69} = 3.14159306054457$$
$$t_{70} = 15.707963957033$$
$$t_{71} = -9.42477744529557$$
$$t_{72} = 53.4070766553897$$
$$t_{73} = -59.6902606928653$$
$$t_{74} = 72.2566306985$$
$$t_{75} = -28.2743343914215$$
$$t_{76} = -97.3893717476911$$
$$t_{77} = 84.8230021335997$$
$$t_{78} = 78.5398168562347$$
$$t_{79} = 65.9734452390837$$
$$t_{80} = -78.5398168194507$$
$$t_{81} = -28.2743337069329$$
$$t_{82} = 78.5398149750205$$
$$t_{83} = 34.5575190219169$$
$$t_{84} = 53.4070746418597$$
$$t_{85} = -72.2566311847166$$
$$t_{86} = 40.8407042062167$$
$$t_{87} = 65.9734460390947$$
$$t_{88} = -15.7079632965989$$
$$t_{89} = 3.1415922548952$$
$$t_{90} = 28.2743335663982$$