El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\cos{\left(5 x - 2 \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = \frac{2}{5} + \frac{3 \pi}{10}$$
$$x_{2} = \frac{\pi}{10} + \frac{2}{5}$$
Solución numérica$$x_{1} = -11.8522113490002$$
$$x_{2} = 56.0061899685393$$
$$x_{3} = -87.8787535658732$$
$$x_{4} = -53.9495529071034$$
$$x_{5} = -33.8433599241287$$
$$x_{6} = -3.05575191894877$$
$$x_{7} = 34.0150413934108$$
$$x_{8} = 2054.68743618237$$
$$x_{9} = -85.9937979737193$$
$$x_{10} = -80.3389311972577$$
$$x_{11} = 20.1920337176157$$
$$x_{12} = 37.1566340470006$$
$$x_{13} = -20.0203522483337$$
$$x_{14} = 61.661056745001$$
$$x_{15} = 64.1743308678728$$
$$x_{16} = -74.0557458900781$$
$$x_{17} = 28.3601746169492$$
$$x_{18} = 72.9707902979242$$
$$x_{19} = -8.08230016469244$$
$$x_{20} = -91.6486647501809$$
$$x_{21} = 30.245130209103$$
$$x_{22} = 54.1212343763855$$
$$x_{23} = -3.68407044966673$$
$$x_{24} = 98.1035315266426$$
$$x_{25} = 67.9442420521806$$
$$x_{26} = -23.7902634326414$$
$$x_{27} = 42.1831822927442$$
$$x_{28} = 57.8911455606932$$
$$x_{29} = -55.8345084992573$$
$$x_{30} = -89.7637091580271$$
$$x_{31} = 72.3424717672063$$
$$x_{32} = -65.8876049907446$$
$$x_{33} = -45.78141200777$$
$$x_{34} = -74.6840644207961$$
$$x_{35} = 45.953093477052$$
$$x_{36} = -82.8522053201295$$
$$x_{37} = 7.62566310325652$$
$$x_{38} = -35.7283155162826$$
$$x_{39} = 84.2805238508475$$
$$x_{40} = -75.940701482232$$
$$x_{41} = 96.2185759344887$$
$$x_{42} = -40.1265452313083$$
$$x_{43} = 99.9884871187964$$
$$x_{44} = 77.9973385436679$$
$$x_{45} = -52.0645973149495$$
$$x_{46} = 79.8822941358218$$
$$x_{47} = -30.073448739821$$
$$x_{48} = 10.1389372261284$$
$$x_{49} = -42.0115008234622$$
$$x_{50} = 1.9707963267949$$
$$x_{51} = 94.3336203423348$$
$$x_{52} = 18.3070781254618$$
$$x_{53} = -96.0468944652066$$
$$x_{54} = 35.8999969855647$$
$$x_{55} = -84.1088423815654$$
$$x_{56} = -58.9761011528471$$
$$x_{57} = -15.6221225333079$$
$$x_{58} = 66.0592864600267$$
$$x_{59} = 25.2185819633594$$
$$x_{60} = 8.25398163397448$$
$$x_{61} = 76.112382951514$$
$$x_{62} = 40.2982267005904$$
$$x_{63} = -79.7106126665397$$
$$x_{64} = 52.2362787842316$$
$$x_{65} = 86.1654794430014$$
$$x_{66} = 0.0858407346410207$$
$$x_{67} = -13.7371669411541$$
$$x_{68} = 83.0238867894116$$
$$x_{69} = -67.7725605828985$$
$$x_{70} = 17.6787595947439$$
$$x_{71} = -43.8964564156161$$
$$x_{72} = 12.0238928182822$$
$$x_{73} = 50.3513231920777$$
$$x_{74} = 62.2893752757189$$
$$x_{75} = -31.9584043319749$$
$$x_{76} = -25.6752190247953$$
$$x_{77} = -69.6575161750524$$
$$x_{78} = 74.2274273593601$$
$$x_{79} = -47.6663675999238$$
$$x_{80} = 22.0769893097696$$
$$x_{81} = -62.1176938064369$$
$$x_{82} = -99.8168056495144$$
$$x_{83} = 44.0681378848981$$
$$x_{84} = 6.36902604182061$$
$$x_{85} = -57.7194640914112$$
$$x_{86} = -64.0026493985908$$
$$x_{87} = -9.96725575684632$$
$$x_{88} = 88.0504350351552$$
$$x_{89} = -97.9318500573605$$
$$x_{90} = 89.9353906273091$$
$$x_{91} = -18.1353966561798$$
$$x_{92} = 13.9088484104361$$
$$x_{93} = -77.8256570743858$$
$$x_{94} = 23.9619449019234$$
$$x_{95} = -1.79911485751286$$
$$x_{96} = 32.1300858012569$$
$$x_{97} = -37.6132711084365$$
$$x_{98} = -21.9053078404875$$