El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$\frac{\sin{\left(x \right)} \cos^{2}{\left(x \right)}}{\sqrt{\sin^{2}{\left(x \right)} + \frac{3}{5}}} + \left(\left(- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right) - \sqrt{\sin^{2}{\left(x \right)} + \frac{3}{5}} \sin{\left(x \right)}\right) = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = 2 \operatorname{atan}{\left(\frac{\sqrt{5} \sqrt{21 - 4 \sqrt{26}}}{5} \right)}$$
$$x_{2} = 2 \operatorname{atan}{\left(\frac{\sqrt{5} \sqrt{4 \sqrt{26} + 21}}{5} \right)}$$
Solución numérica$$x_{1} = 33.8885551152193$$
$$x_{2} = 77.8708522654764$$
$$x_{3} = 63.5008171460643$$
$$x_{4} = 69.7840024532439$$
$$x_{5} = 40.1717404223989$$
$$x_{6} = 38.3680759173459$$
$$x_{7} = 0.668964074268407$$
$$x_{8} = -99.862000840605$$
$$x_{9} = -93.5788155334254$$
$$x_{10} = -37.0301477688091$$
$$x_{11} = -79.2087804140132$$
$$x_{12} = 19.5185199958072$$
$$x_{13} = -10.0937420350378$$
$$x_{14} = -18.1805918472704$$
$$x_{15} = -16.3769273422174$$
$$x_{16} = -85.4919657211928$$
$$x_{17} = -62.1628889975275$$
$$x_{18} = -43.3133330759887$$
$$x_{19} = -24.4637771544499$$
$$x_{20} = 90.4372228798356$$
$$x_{21} = 84.154037572656$$
$$x_{22} = -3421.86336383355$$
$$x_{23} = -55.8797036903479$$
$$x_{24} = -35.2264832637561$$
$$x_{25} = 76.0671877604235$$
$$x_{26} = -60.3592244924745$$
$$x_{27} = 25.8017053029868$$
$$x_{28} = 32.0848906101663$$
$$x_{29} = -54.0760391852949$$
$$x_{30} = -91.7751510283724$$
$$x_{31} = 109.286778801374$$
$$x_{32} = 2.47262857932139$$
$$x_{33} = -5.61422123291118$$
$$x_{34} = -123.19107756427$$
$$x_{35} = 8.75581388650097$$
$$x_{36} = 82.350373067603$$
$$x_{37} = -3.8105567278582$$
$$x_{38} = 52.7381110367581$$
$$x_{39} = 21.3221845008601$$
$$x_{40} = 96.7204081870152$$
$$x_{41} = -41.5096685709357$$
$$x_{42} = 46.4549257295785$$
$$x_{43} = -162.693853912401$$
$$x_{44} = -47.7928538781153$$
$$x_{45} = -49.5965183831683$$
$$x_{46} = -98.058336335552$$
$$x_{47} = 44.6512612245255$$
$$x_{48} = -11.8974065400908$$
$$x_{49} = -68.446074304707$$