El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\tan{\left(5 x^{3} - 3 x^{2} \right)} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = \frac{3}{5}$$
$$x_{2} = \frac{2^{\frac{2}{3}} \left(- 8 \sqrt[3]{2} + \sqrt[3]{2} \left(1 - \sqrt{3} i\right) \left(2 + 2 \sqrt{3} i\right)\right)}{40 \left(1 - \sqrt{3} i\right)}$$
$$x_{3} = \frac{2^{\frac{2}{3}} \left(- 8 \sqrt[3]{2} + \sqrt[3]{2} \left(1 + \sqrt{3} i\right) \left(2 - 2 \sqrt{3} i\right)\right)}{40 \left(1 + \sqrt{3} i\right)}$$
Solución numérica$$x_{1} = 48.7122633366659$$
$$x_{2} = 98.2179258578267$$
$$x_{3} = -18.1627568360519$$
$$x_{4} = 21.2571707113263$$
$$x_{5} = 10.0324938320903$$
$$x_{6} = 96.2509759142032$$
$$x_{7} = -37.7499997516132$$
$$x_{8} = 60.0606776073833$$
$$x_{9} = -41.8151070498997$$
$$x_{10} = 56.0755795707334$$
$$x_{11} = 32.0663378886902$$
$$x_{12} = 36.2052629681577$$
$$x_{13} = 77.8008339887773$$
$$x_{14} = 64.0090164931967$$
$$x_{15} = 82.2502505451785$$
$$x_{16} = -53.7493550992879$$
$$x_{17} = -49.7177501815055$$
$$x_{18} = -53.9080635999454$$
$$x_{19} = 92.191367017249$$
$$x_{20} = 30.3686847163059$$
$$x_{21} = -13.7532843683611$$
$$x_{22} = 34.2995866056314$$
$$x_{23} = -25.7698695114996$$
$$x_{24} = -91.8705702093327$$
$$x_{25} = 44.0481144024558$$
$$x_{26} = -96.8686512891129$$
$$x_{27} = -41.007104086909$$
$$x_{28} = -96.2595660491577$$
$$x_{29} = 84.5147420451521$$
$$x_{30} = 88.5511478334227$$
$$x_{31} = 80.2866929187456$$
$$x_{32} = 50.0295948990548$$
$$x_{33} = -28.1278544202307$$
$$x_{34} = 20.2373449531415$$
$$x_{35} = -9.2632547366563$$
$$x_{36} = 61.9065210404182$$
$$x_{37} = -4.22415327796343$$
$$x_{38} = 46.2603738117288$$
$$x_{39} = 58.3495797354778$$
$$x_{40} = -78.5906465693487$$
$$x_{41} = 0$$
$$x_{42} = -97.8230255989836$$
$$x_{43} = -63.7981624052064$$
$$x_{44} = 28.4125557669919$$
$$x_{45} = 76.9054274280986$$
$$x_{46} = 52.0696529185049$$
$$x_{47} = -76.0098215604941$$
$$x_{48} = -57.6942557254626$$
$$x_{49} = -3.02917278455781$$
$$x_{50} = -60.1059534766723$$
$$x_{51} = -23.3697813947453$$
$$x_{52} = -87.5824059943948$$
$$x_{53} = 16.2457685310201$$
$$x_{54} = 2.18266194714764$$
$$x_{55} = -67.7588881842643$$
$$x_{56} = -74.1444947322395$$
$$x_{57} = 100.250275863721$$
$$x_{58} = -21.8342896026477$$
$$x_{59} = 90.249609516813$$
$$x_{60} = 18.2499949333188$$
$$x_{61} = -55.8923551209742$$
$$x_{62} = 74.2076536675375$$
$$x_{63} = 13.995548606494$$
$$x_{64} = -9.3237014346457$$
$$x_{65} = -61.7502707301589$$
$$x_{66} = -86.0771002607148$$
$$x_{67} = 66.2905823859236$$
$$x_{68} = 12.1914392274017$$
$$x_{69} = -36.0337053916817$$
$$x_{70} = -38.6890135176372$$
$$x_{71} = 38.8717658557628$$
$$x_{72} = 4.27635096215856$$
$$x_{73} = 68.2035754358032$$
$$x_{74} = -97.9220817279324$$
$$x_{75} = -17.4804837702978$$
$$x_{76} = -82.0488414226693$$
$$x_{77} = -15.7499662433599$$
$$x_{78} = 70.0915612338689$$
$$x_{79} = 40.1922099296423$$
$$x_{80} = 86.0384218076054$$
$$x_{81} = 70.1891389874686$$
$$x_{82} = -69.7954214327999$$
$$x_{83} = -10.9075483225474$$
$$x_{84} = -65.9737155360911$$
$$x_{85} = 6.38851837733585$$
$$x_{86} = 94.241568336463$$
$$x_{87} = -43.9803412363171$$
$$x_{88} = -79.4284155197799$$
$$x_{89} = 7.60575485438076$$
$$x_{90} = -47.7750344838465$$
$$x_{91} = -41.5300856273978$$
$$x_{92} = -1.88241934891871$$
$$x_{93} = -27.9856759437344$$
$$x_{94} = 26.2491462990014$$
$$x_{95} = 52.2203920800048$$
$$x_{96} = 24.2876898199067$$