Para hallar los extremos hay que resolver la ecuación
$$\frac{d}{d x} f{\left(x \right)} = 0$$
(la derivada es igual a cero),
y las raíces de esta ecuación serán los extremos de esta función:
$$\frac{d}{d x} f{\left(x \right)} = $$
primera derivada$$- 3 \left(4 \tan^{2}{\left(x \right)} + 4\right) \tan^{3}{\left(x \right)} + \cos{\left(x \right)} \operatorname{sign}{\left(\sin{\left(x \right)} \right)} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 81.2967143466105$$
$$x_{2} = 25.5174358754425$$
$$x_{3} = 53.0223804643024$$
$$x_{4} = 90.7214923073799$$
$$x_{5} = -56.9333624113404$$
$$x_{6} = -46.7391951571228$$
$$x_{7} = 38.0838064898016$$
$$x_{8} = 62.4471584250717$$
$$x_{9} = -40.4560098499432$$
$$x_{10} = -2.75689800686566$$
$$x_{11} = -93.8630849609697$$
$$x_{12} = -68.7303437322513$$
$$x_{13} = 24.7480465819942$$
$$x_{14} = -9.80947260749351$$
$$x_{15} = 60.0749550649302$$
$$x_{16} = -27.889639235584$$
$$x_{17} = -53.7917697577506$$
$$x_{18} = -34.1728245427636$$
$$x_{19} = -19.2342505682629$$
$$x_{20} = 91.4908816008281$$
$$x_{21} = 66.3581403721098$$
$$x_{22} = -71.8719363858411$$
$$x_{23} = -5.89849066045546$$
$$x_{24} = 88.3492889472383$$
$$x_{25} = -91.4908816008281$$
$$x_{26} = 75.7829183328792$$
$$x_{27} = 100.146270268149$$
$$x_{28} = -43.597602503533$$
$$x_{29} = 63.21654771852$$
$$x_{30} = -63.21654771852$$
$$x_{31} = 22.3758432218527$$
$$x_{32} = -31.8006211826221$$
$$x_{33} = 31.8006211826221$$
$$x_{34} = -100.146270268149$$
$$x_{35} = 19.2342505682629$$
$$x_{36} = 0$$
$$x_{37} = -62.4471584250717$$
$$x_{38} = -34.9422138362119$$
$$x_{39} = 68.7303437322513$$
$$x_{40} = 18.4648612748146$$
$$x_{41} = -82.0661036400588$$
$$x_{42} = -78.924510986469$$
$$x_{43} = 97.7740669080077$$
$$x_{44} = 12.181675967635$$
$$x_{45} = -25.5174358754425$$
$$x_{46} = -56.1639731178921$$
$$x_{47} = -3.52628730031392$$
$$x_{48} = -41.2253991433914$$
$$x_{49} = -49.8807878107126$$
$$x_{50} = 97.0046776145595$$
$$x_{51} = -69.4997330256996$$
$$x_{52} = 129.189993443906$$
$$x_{53} = 85.2076962936485$$
$$x_{54} = -84.4383070002003$$
$$x_{55} = 46.7391951571228$$
$$x_{56} = 44.3669917969812$$
$$x_{57} = -85.2076962936485$$
$$x_{58} = -38.0838064898016$$
$$x_{59} = -21.6064539284044$$
$$x_{60} = -53.0223804643024$$
$$x_{61} = 59.3055657714819$$
$$x_{62} = -12.9510652610833$$
$$x_{63} = 31.0312318891738$$
$$x_{64} = 3.52628730031392$$
$$x_{65} = 41.2253991433914$$
$$x_{66} = 40.4560098499432$$
$$x_{67} = 53.7917697577506$$
$$x_{68} = 2.75689800686566$$
$$x_{69} = -47.508584450571$$
$$x_{70} = -78.1551216930207$$
$$x_{71} = -12.181675967635$$
$$x_{72} = -16.0926579146731$$
$$x_{73} = 82.0661036400588$$
$$x_{74} = -97.0046776145595$$
$$x_{75} = -90.7214923073799$$
$$x_{76} = 69.4997330256996$$
$$x_{77} = 47.508584450571$$
$$x_{78} = 84.4383070002003$$
$$x_{79} = 37.3144171963534$$
$$x_{80} = 16.0926579146731$$
$$x_{81} = -75.7829183328792$$
$$x_{82} = -24.7480465819942$$
$$x_{83} = 75.0135290394309$$
$$x_{84} = 9.04008331404525$$
$$x_{85} = -75.0135290394309$$
$$x_{86} = 78.1551216930207$$
$$x_{87} = -97.7740669080077$$
$$x_{88} = 34.1728245427636$$
$$x_{89} = 9.80947260749351$$
$$x_{90} = -18.4648612748146$$
$$x_{91} = -31.0312318891738$$
$$x_{92} = -60.0749550649302$$
$$x_{93} = 56.1639731178921$$
Signos de extremos en los puntos:
(81.2967143466105, 1.29466982577999)
(25.517435875442473, 1.29466982577999)
(53.02238046430236, 1.29466982577999)
(90.72149230737988, 1.29466982577999)
(-56.933362411340404, 1.29466982577999)
(-46.73919515712277, 1.29466982577999)
(38.083806489801646, 1.29466982577999)
(62.447158425071734, 1.29466982577999)
(-40.456009849943186, 1.29466982577999)
(-2.756898006865665, 1.29466982577999)
(-93.86308496096967, 1.29466982577999)
(-68.73034373225133, 1.29466982577999)
(24.748046581994217, 1.29466982577999)
(-9.809472607493507, 1.29466982577999)
(60.0749550649302, 1.29466982577999)
(-27.88963923558401, 1.29466982577999)
(-53.791769757750615, 1.29466982577999)
(-34.1728245427636, 1.29466982577999)
(-19.234250568262887, 1.29466982577998)
(91.49088160082813, 1.29466982577999)
(66.35814037210979, 1.29466982577999)
(-71.87193638584111, 1.29466982577999)
(-5.898490660455458, 1.29466982577999)
(88.34928894723834, 1.29466982577999)
(-91.49088160082813, 1.29466982577999)
(75.78291833287916, 1.29466982577999)
(100.14627026814925, 1.29466982577999)
(-43.597602503532976, 1.29466982577999)
(63.21654771851999, 1.29466982577999)
(-63.21654771851999, 1.29466982577999)
(22.37584322185268, 1.29466982577999)
(-31.80062118262206, 1.29466982577999)
(31.80062118262206, 1.29466982577999)
(-100.14627026814925, 1.29466982577999)
(19.234250568262887, 1.29466982577998)
(0, 1)
(-62.447158425071734, 1.29466982577999)
(-34.942213836211856, 1.29466982577998)
(68.73034373225133, 1.29466982577999)
(18.46486127481463, 1.29466982577999)
(-82.06610364005876, 1.29466982577999)
(-78.92451098646896, 1.29466982577999)
(97.77406690800773, 1.29466982577999)
(12.181675967635044, 1.29466982577999)
(-25.517435875442473, 1.29466982577999)
(-56.16397311789215, 1.29466982577998)
(-3.5262873003139217, 1.29466982577999)
(-41.22539914339144, 1.29466982577999)
(-49.88078781071256, 1.29466982577999)
(97.00467761455947, 1.29466982577999)
(-69.49973302569958, 1.29466982577999)
(129.18999344390565, 1.29466982577999)
(85.20769629364854, 1.29466982577999)
(-84.43830700020028, 1.29466982577999)
(46.73919515712277, 1.29466982577999)
(44.36699179698123, 1.29466982577999)
(-85.20769629364854, 1.29466982577999)
(-38.083806489801646, 1.29466982577999)
(-21.606453928404424, 1.29466982577999)
(-53.02238046430236, 1.29466982577999)
(59.305565771481945, 1.29466982577999)
(-12.9510652610833, 1.29466982577999)
(31.031231889173803, 1.29466982577999)
(3.5262873003139217, 1.29466982577999)
(41.22539914339144, 1.29466982577999)
(40.456009849943186, 1.29466982577999)
(53.791769757750615, 1.29466982577999)
(2.756898006865665, 1.29466982577999)
(-47.50858445057103, 1.29466982577999)
(-78.1551216930207, 1.29466982577999)
(-12.181675967635044, 1.29466982577999)
(-16.092657914673094, 1.29466982577999)
(82.06610364005876, 1.29466982577999)
(-97.00467761455947, 1.29466982577999)
(-90.72149230737988, 1.29466982577999)
(69.49973302569958, 1.29466982577999)
(47.50858445057103, 1.29466982577999)
(84.43830700020028, 1.29466982577999)
(37.31441719635339, 1.29466982577999)
(16.092657914673094, 1.29466982577999)
(-75.78291833287916, 1.29466982577999)
(-24.748046581994217, 1.29466982577999)
(75.0135290394309, 1.29466982577999)
(9.040083314045251, 1.29466982577999)
(-75.0135290394309, 1.29466982577999)
(78.1551216930207, 1.29466982577999)
(-97.77406690800773, 1.29466982577999)
(34.1728245427636, 1.29466982577999)
(9.809472607493507, 1.29466982577999)
(-18.46486127481463, 1.29466982577999)
(-31.031231889173803, 1.29466982577999)
(-60.0749550649302, 1.29466982577999)
(56.16397311789215, 1.29466982577998)
Intervalos de crecimiento y decrecimiento de la función:Hallemos los intervalos donde la función crece y decrece y también los puntos mínimos y máximos de la función, para lo cual miramos cómo se comporta la función en los extremos con desviación mínima del extremo:
Puntos mínimos de la función:
$$x_{1} = 0$$
Puntos máximos de la función:
$$x_{1} = 81.2967143466105$$
$$x_{1} = 25.5174358754425$$
$$x_{1} = 53.0223804643024$$
$$x_{1} = 90.7214923073799$$
$$x_{1} = -56.9333624113404$$
$$x_{1} = -46.7391951571228$$
$$x_{1} = 38.0838064898016$$
$$x_{1} = 62.4471584250717$$
$$x_{1} = -40.4560098499432$$
$$x_{1} = -2.75689800686566$$
$$x_{1} = -93.8630849609697$$
$$x_{1} = -68.7303437322513$$
$$x_{1} = 24.7480465819942$$
$$x_{1} = -9.80947260749351$$
$$x_{1} = 60.0749550649302$$
$$x_{1} = -27.889639235584$$
$$x_{1} = -53.7917697577506$$
$$x_{1} = -34.1728245427636$$
$$x_{1} = -19.2342505682629$$
$$x_{1} = 91.4908816008281$$
$$x_{1} = 66.3581403721098$$
$$x_{1} = -71.8719363858411$$
$$x_{1} = -5.89849066045546$$
$$x_{1} = 88.3492889472383$$
$$x_{1} = -91.4908816008281$$
$$x_{1} = 75.7829183328792$$
$$x_{1} = 100.146270268149$$
$$x_{1} = -43.597602503533$$
$$x_{1} = 63.21654771852$$
$$x_{1} = -63.21654771852$$
$$x_{1} = 22.3758432218527$$
$$x_{1} = -31.8006211826221$$
$$x_{1} = 31.8006211826221$$
$$x_{1} = -100.146270268149$$
$$x_{1} = 19.2342505682629$$
$$x_{1} = -62.4471584250717$$
$$x_{1} = -34.9422138362119$$
$$x_{1} = 68.7303437322513$$
$$x_{1} = 18.4648612748146$$
$$x_{1} = -82.0661036400588$$
$$x_{1} = -78.924510986469$$
$$x_{1} = 97.7740669080077$$
$$x_{1} = 12.181675967635$$
$$x_{1} = -25.5174358754425$$
$$x_{1} = -56.1639731178921$$
$$x_{1} = -3.52628730031392$$
$$x_{1} = -41.2253991433914$$
$$x_{1} = -49.8807878107126$$
$$x_{1} = 97.0046776145595$$
$$x_{1} = -69.4997330256996$$
$$x_{1} = 129.189993443906$$
$$x_{1} = 85.2076962936485$$
$$x_{1} = -84.4383070002003$$
$$x_{1} = 46.7391951571228$$
$$x_{1} = 44.3669917969812$$
$$x_{1} = -85.2076962936485$$
$$x_{1} = -38.0838064898016$$
$$x_{1} = -21.6064539284044$$
$$x_{1} = -53.0223804643024$$
$$x_{1} = 59.3055657714819$$
$$x_{1} = -12.9510652610833$$
$$x_{1} = 31.0312318891738$$
$$x_{1} = 3.52628730031392$$
$$x_{1} = 41.2253991433914$$
$$x_{1} = 40.4560098499432$$
$$x_{1} = 53.7917697577506$$
$$x_{1} = 2.75689800686566$$
$$x_{1} = -47.508584450571$$
$$x_{1} = -78.1551216930207$$
$$x_{1} = -12.181675967635$$
$$x_{1} = -16.0926579146731$$
$$x_{1} = 82.0661036400588$$
$$x_{1} = -97.0046776145595$$
$$x_{1} = -90.7214923073799$$
$$x_{1} = 69.4997330256996$$
$$x_{1} = 47.508584450571$$
$$x_{1} = 84.4383070002003$$
$$x_{1} = 37.3144171963534$$
$$x_{1} = 16.0926579146731$$
$$x_{1} = -75.7829183328792$$
$$x_{1} = -24.7480465819942$$
$$x_{1} = 75.0135290394309$$
$$x_{1} = 9.04008331404525$$
$$x_{1} = -75.0135290394309$$
$$x_{1} = 78.1551216930207$$
$$x_{1} = -97.7740669080077$$
$$x_{1} = 34.1728245427636$$
$$x_{1} = 9.80947260749351$$
$$x_{1} = -18.4648612748146$$
$$x_{1} = -31.0312318891738$$
$$x_{1} = -60.0749550649302$$
$$x_{1} = 56.1639731178921$$
Decrece en los intervalos
$$\left(-\infty, -100.146270268149\right] \cup \left[0, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, 0\right] \cup \left[129.189993443906, \infty\right)$$