El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
$$- \sqrt{2} \sqrt{\frac{\left(-1\right) \cos^{4}{\left(x \right)}}{\sin{\left(x \right)}}} = 0$$
Resolvermos esta ecuaciónPuntos de cruce con el eje X:
Solución analítica$$x_{1} = \frac{\pi}{2}$$
$$x_{2} = \frac{3 \pi}{2}$$
Solución numérica$$x_{1} = -36.128315417303$$
$$x_{2} = 10.9955748658775$$
$$x_{3} = -70.6858352925094$$
$$x_{4} = -73.8274272798452$$
$$x_{5} = 54.977872035211$$
$$x_{6} = 64.4026493071867$$
$$x_{7} = 89.5353908915565$$
$$x_{8} = -76.9690194689577$$
$$x_{9} = 17.2787599776887$$
$$x_{10} = -98.9601689789469$$
$$x_{11} = 17.278759042785$$
$$x_{12} = 10.9955739190651$$
$$x_{13} = -48.6946867082606$$
$$x_{14} = 51.8362789032226$$
$$x_{15} = -54.9778708856812$$
$$x_{16} = 39.2699085572834$$
$$x_{17} = 80.1106131362399$$
$$x_{18} = 83.2522057166288$$
$$x_{19} = -76.9690203992439$$
$$x_{20} = 26.7035373204775$$
$$x_{21} = -64.402649162459$$
$$x_{22} = 73.827427483168$$
$$x_{23} = -20.420352004125$$
$$x_{24} = 45.5530937333057$$
$$x_{25} = 36.1283157048051$$
$$x_{26} = 54.9778710779606$$
$$x_{27} = -4.71238860185859$$
$$x_{28} = -54.9778718195945$$
$$x_{29} = 14.1371671102992$$
$$x_{30} = -45.5530935911667$$
$$x_{31} = 61.2610571369289$$
$$x_{32} = -61.2610569959307$$
$$x_{33} = -58.1194639976623$$
$$x_{34} = 32.9867234503679$$
$$x_{35} = -23.5619450115645$$
$$x_{36} = 23.5619451541703$$
$$x_{37} = 86.3937978869722$$
$$x_{38} = -92.6769838770703$$
$$x_{39} = 58.1194643805018$$
$$x_{40} = 1.57079657502703$$
$$x_{41} = -14.1371668370446$$
$$x_{42} = -42.4115005832868$$
$$x_{43} = -83.2522055750209$$
$$x_{44} = 39.2699076259512$$
$$x_{45} = 32.986722498532$$
$$x_{46} = 7.85398174312344$$
$$x_{47} = -80.1106125781344$$
$$x_{48} = 29.8451303232099$$
$$x_{49} = 67.5442423124342$$
$$x_{50} = -95.8185758680503$$
$$x_{51} = -48.6946857608237$$
$$x_{52} = 92.6769830578528$$
$$x_{53} = -10.9955746604431$$
$$x_{54} = 61.2610562088823$$
$$x_{55} = -26.7035381243061$$
$$x_{56} = 98.9601692060476$$
$$x_{57} = -86.3937977416427$$
$$x_{58} = -4.71238954062934$$
$$x_{59} = 76.9690206204294$$
$$x_{60} = 4.71238874136685$$
$$x_{61} = -10.9955737182813$$
$$x_{62} = -39.2699084168366$$
$$x_{63} = 70.6858344787198$$
$$x_{64} = -29.8451300954811$$
$$x_{65} = -17.2787598377376$$
$$x_{66} = -26.7035371813617$$
$$x_{67} = -32.9867223021281$$
$$x_{68} = -70.6858343402476$$
$$x_{69} = -51.8362786893266$$
$$x_{70} = -98.9601680519735$$
$$x_{71} = -32.9867232399952$$
$$x_{72} = 48.6946858995949$$
$$x_{73} = 76.9690196573535$$
$$x_{74} = -1.5707964319302$$
$$x_{75} = -92.6769829196362$$
$$x_{76} = 20.4203521477382$$
$$x_{77} = 42.4115007274429$$
$$x_{78} = 83.2522047915908$$
$$x_{79} = -7.85398149661834$$
$$x_{80} = -67.5442421707388$$
$$x_{81} = -89.5353907502823$$
$$x_{82} = 95.8185760630519$$
$$x_{83} = 98.9601682367132$$