El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\tan{\left(x \right)} + 3 = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = - \operatorname{atan}{\left(3 \right)}$$
Solución numérica$$x_{1} = -42.0897502690656$$
$$x_{2} = -73.5056768049635$$
$$x_{3} = -45.2313429226554$$
$$x_{4} = 1.89254688119154$$
$$x_{5} = 64.7243999529874$$
$$x_{6} = 52.1580293386282$$
$$x_{7} = 74.1491779137568$$
$$x_{8} = 42.7332513778588$$
$$x_{9} = 96.1403264888853$$
$$x_{10} = -35.806564961886$$
$$x_{11} = 23.8836954563201$$
$$x_{12} = 89.8571411817058$$
$$x_{13} = 45.8748440314486$$
$$x_{14} = -2599.34617029116$$
$$x_{15} = 240.653588554016$$
$$x_{16} = -26.3817870011166$$
$$x_{17} = -29.5233796547064$$
$$x_{18} = 36.4500660706793$$
$$x_{19} = 58.4412146458078$$
$$x_{20} = -13.8154163867574$$
$$x_{21} = 17.6005101491405$$
$$x_{22} = -86.0720474193227$$
$$x_{23} = -20.098601693937$$
$$x_{24} = 80.4323632209364$$
$$x_{25} = -4022.48764236733$$
$$x_{26} = 8.17573218837112$$
$$x_{27} = -7.53223107957784$$
$$x_{28} = -51.5145282298349$$
$$x_{29} = 14.4589174955507$$
$$x_{30} = 77.2907705673466$$
$$x_{31} = -48.3729355762452$$
$$x_{32} = -1.24904577239825$$
$$x_{33} = -79.7888621121431$$
$$x_{34} = -64.0808988441941$$
$$x_{35} = 67.8659926065772$$
$$x_{36} = 30.1668807634997$$
$$x_{37} = 86.715548528116$$
$$x_{38} = -57.7977135370145$$