El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$- \frac{2 \sin{\left(3 x \right)}}{25} + \frac{\left(-1\right) 3 \cos{\left(3 x \right)}}{50} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \frac{\operatorname{atan}{\left(\frac{3}{4} \right)}}{3}$$
Solución numérica$$x_{1} = -77.707119158146$$
$$x_{2} = 86.7028963797198$$
$$x_{3} = 80.4197110725403$$
$$x_{4} = 25.9654384103172$$
$$x_{5} = 89.8444890333096$$
$$x_{6} = 50.0509820878389$$
$$x_{7} = -88.179094670112$$
$$x_{8} = -68.2823411973766$$
$$x_{9} = 185.1394661922$$
$$x_{10} = 12.3518702447614$$
$$x_{11} = 1.87989473279543$$
$$x_{12} = 54.2397722926253$$
$$x_{13} = 45.8621918830525$$
$$x_{14} = 47.9565869854457$$
$$x_{15} = -74.5655265045562$$
$$x_{16} = -91.3206873237018$$
$$x_{17} = 78.3253159701471$$
$$x_{18} = 82.5141061749335$$
$$x_{19} = 21.7766482055308$$
$$x_{20} = 91.9388841357028$$
$$x_{21} = 94.033279238096$$
$$x_{22} = 52.1453771902321$$
$$x_{23} = 60.5229575998049$$
$$x_{24} = 61.5701551510015$$
$$x_{25} = 28.0598335127104$$
$$x_{26} = -86.0846995677188$$
$$x_{27} = 98.2220694428824$$
$$x_{28} = -90.2734897725052$$
$$x_{29} = -51.5271803782311$$
$$x_{30} = -44.1967975198549$$
$$x_{31} = 3.97428983518863$$
$$x_{32} = 6.06868493758182$$
$$x_{33} = -95.5094775284882$$
$$x_{34} = 32.2486237174968$$
$$x_{35} = -2.30889547199096$$
$$x_{36} = 58.4285624974117$$
$$x_{37} = -0.214500369597761$$
$$x_{38} = -81.8959093629324$$
$$x_{39} = -22.2056489447263$$
$$x_{40} = -57.8103656854106$$
$$x_{41} = 56.3341673950185$$
$$x_{42} = -75.6127240557528$$
$$x_{43} = 3515.22767899738$$
$$x_{44} = -15.9224636375467$$
$$x_{45} = -61.999155890197$$
$$x_{46} = 67.8533404581811$$
$$x_{47} = -9.63927833036714$$
$$x_{48} = -27.4416367007093$$
$$x_{49} = -59.9047607878038$$
$$x_{50} = -42.1024024174617$$
$$x_{51} = -99.6982677332745$$
$$x_{52} = 38.5318090246764$$
$$x_{53} = 34.34301881989$$
$$x_{54} = 96.1276743404892$$
$$x_{55} = -66.1879460949834$$
$$x_{56} = -24.3000440471195$$
$$x_{57} = -70.3767362997698$$
$$x_{58} = 43.7677967806593$$
$$x_{59} = 14.4462653471546$$
$$x_{60} = -18.0168587399399$$
$$x_{61} = 69.9477355605743$$
$$x_{62} = -31.6304269054957$$
$$x_{63} = -20.1112538423331$$
$$x_{64} = -97.6038726308814$$
$$x_{65} = 30.1542286151036$$
$$x_{66} = 87.7500939309164$$
$$x_{67} = -40.0080073150685$$
$$x_{68} = -94.4622799772916$$
$$x_{69} = -92.3678848748984$$
$$x_{70} = -35.8192171102821$$
$$x_{71} = -83.9903044653256$$
$$x_{72} = 72.0421306629675$$
$$x_{73} = -55.7159705830174$$
$$x_{74} = -46.2911926222481$$
$$x_{75} = -37.9136122126753$$
$$x_{76} = -73.5183289533596$$
$$x_{77} = 23.871043307924$$
$$x_{78} = 76.2309208677539$$
$$x_{79} = -29.5360318031025$$
$$x_{80} = -11.7336734327603$$
$$x_{81} = -13.8280685351535$$
$$x_{82} = -47.3383901734447$$
$$x_{83} = -33.7248220078889$$
$$x_{84} = -64.0935509925902$$
$$x_{85} = 8.16308003997502$$
$$x_{86} = -79.8015142605392$$
$$x_{87} = 64.7117478045913$$
$$x_{88} = -7.54488322797395$$
$$x_{89} = 65.7589453557879$$
$$x_{90} = 40.6262041270695$$
$$x_{91} = 74.1365257653607$$
$$x_{92} = 44.8149943318559$$
$$x_{93} = 16.5406604495478$$
$$x_{94} = 100.316464545276$$
$$x_{95} = -5.45048812558075$$
$$x_{96} = 17.5878580007444$$
$$x_{97} = 36.4374139222832$$
$$x_{98} = 10.2574751423682$$
$$x_{99} = -53.6215754806242$$