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$$- \frac{x^{5} \cos{\left(x \right)}}{\sin^{2}{\left(x \right)}} + \frac{5 x^{4}}{\sin{\left(x \right)}} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 10.5531104299019$$
$$x_{2} = -29.6782238599607$$
$$x_{3} = 42.2938264412084$$
$$x_{4} = -32.8356099874983$$
$$x_{5} = -51.7399407908695$$
$$x_{6} = 26.5171686179843$$
$$x_{7} = -61.1795112699548$$
$$x_{8} = -45.4435075515668$$
$$x_{9} = -89.4795700005049$$
$$x_{10} = 39.1428589802905$$
$$x_{11} = -13.7893118576574$$
$$x_{12} = 45.4435075515668$$
$$x_{13} = 83.1921757248865$$
$$x_{14} = -64.3250751965547$$
$$x_{15} = -58.0335192248369$$
$$x_{16} = -42.2938264412084$$
$$x_{17} = 58.0335192248369$$
$$x_{18} = 20.1774438696657$$
$$x_{19} = 54.8870259692204$$
$$x_{20} = -80.0482313681549$$
$$x_{21} = 32.8356099874983$$
$$x_{22} = 98.909660402511$$
$$x_{23} = -39.1428589802905$$
$$x_{24} = -3.79022237829253$$
$$x_{25} = -23.3510066366273$$
$$x_{26} = -73.7597432512514$$
$$x_{27} = 92.6230533845309$$
$$x_{28} = 16.9925901138555$$
$$x_{29} = 51.7399407908695$$
$$x_{30} = -67.4702705534315$$
$$x_{31} = 73.7597432512514$$
$$x_{32} = -92.6230533845309$$
$$x_{33} = 67.4702705534315$$
$$x_{34} = 76.9040953473809$$
$$x_{35} = -54.8870259692204$$
$$x_{36} = 35.9902726647882$$
$$x_{37} = -26.5171686179843$$
$$x_{38} = 29.6782238599607$$
$$x_{39} = 61.1795112699548$$
$$x_{40} = 7.25024830711031$$
$$x_{41} = 95.7664129259896$$
$$x_{42} = 70.6151463420358$$
$$x_{43} = 64.3250751965547$$
$$x_{44} = 48.5921497153139$$
$$x_{45} = -7.25024830711031$$
$$x_{46} = -95.7664129259896$$
$$x_{47} = -16.9925901138555$$
$$x_{48} = 23.3510066366273$$
$$x_{49} = -10.5531104299019$$
$$x_{50} = 89.4795700005049$$
$$x_{51} = 86.335949286752$$
$$x_{52} = -76.9040953473809$$
$$x_{53} = -70.6151463420358$$
$$x_{54} = 13.7893118576574$$
$$x_{55} = 3.79022237829253$$
$$x_{56} = 80.0482313681549$$
$$x_{57} = -20.1774438696657$$
$$x_{58} = -83.1921757248865$$
$$x_{59} = -35.9902726647882$$
$$x_{60} = -98.909660402511$$
$$x_{61} = -48.5921497153139$$
$$x_{62} = -86.335949286752$$
Signos de extremos en los puntos:
(10.553110429901942, -144836.622542368)
(-29.67822385996075, -23348933.9988476)
(42.29382644120838, -136269528.568455)
(-32.835609987498266, 38610285.1882944)
(-51.739940790869504, 372518724.77898)
(26.517168617984314, 13342035.1057279)
(-61.17951126995476, -859954703.185496)
(-45.44350755156676, 194971978.395094)
(-89.47957000050494, 5745084383.58212)
(39.142858980290455, 92635461.1324094)
(-13.789311857657383, 530317.704370101)
(45.44350755156676, 194971978.395094)
(83.19217572488648, 3992044599.32892)
(-64.32507519655475, 1104611511.64742)
(-58.03351922483685, 660694176.070092)
(-42.29382644120838, -136269528.568455)
(58.03351922483685, 660694176.070092)
(20.177443869665733, 3445652.04683287)
(54.88702596922039, -500199279.101362)
(-80.04823136815494, -3293095042.76767)
(32.835609987498266, 38610285.1882944)
(98.90966040251095, -9478677533.92323)
(-39.142858980290455, 92635461.1324094)
(-3.7902223782925293, -1294.84632241203)
(-23.351006636627282, -7100067.9578743)
(-73.75974325125135, -2188227762.21252)
(92.6230533845309, -6826959607.90923)
(16.992590113855474, -1476824.51218319)
(51.739940790869504, 372518724.77898)
(-67.47027055343149, -1402011338.71759)
(73.75974325125135, -2188227762.21252)
(-92.6230533845309, -6826959607.90923)
(67.47027055343149, -1402011338.71759)
(76.9040953473809, 2695648764.73051)
(-54.88702596922039, -500199279.101362)
(35.99027266478819, -60964471.6454713)
(-26.517168617984314, 13342035.1057279)
(29.67822385996075, -23348933.9988476)
(61.17951126995476, -859954703.185496)
(7.250248307110308, 24335.9050167958)
(95.76641292598956, 8065981548.75513)
(70.61514634203581, 1760253730.08186)
(64.32507519655475, 1104611511.64742)
(48.592149715313944, -272343866.939746)
(-7.250248307110308, 24335.9050167958)
(-95.76641292598956, 8065981548.75513)
(-16.992590113855474, -1476824.51218319)
(23.351006636627282, -7100067.9578743)
(-10.553110429901942, -144836.622542368)
(89.47957000050494, 5745084383.58212)
(86.33594928675204, -4804911857.65449)
(-76.9040953473809, 2695648764.73051)
(-70.61514634203581, 1760253730.08186)
(13.789311857657383, 530317.704370101)
(3.7902223782925293, -1294.84632241203)
(80.04823136815494, -3293095042.76767)
(-20.177443869665733, 3445652.04683287)
(-83.19217572488648, 3992044599.32892)
(-35.99027266478819, -60964471.6454713)
(-98.90966040251095, -9478677533.92323)
(-48.592149715313944, -272343866.939746)
(-86.33594928675204, -4804911857.65449)
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:
$$x_{1} = -32.8356099874983$$
$$x_{2} = -51.7399407908695$$
$$x_{3} = 26.5171686179843$$
$$x_{4} = -45.4435075515668$$
$$x_{5} = -89.4795700005049$$
$$x_{6} = 39.1428589802905$$
$$x_{7} = -13.7893118576574$$
$$x_{8} = 45.4435075515668$$
$$x_{9} = 83.1921757248865$$
$$x_{10} = -64.3250751965547$$
$$x_{11} = -58.0335192248369$$
$$x_{12} = 58.0335192248369$$
$$x_{13} = 20.1774438696657$$
$$x_{14} = 32.8356099874983$$
$$x_{15} = -39.1428589802905$$
$$x_{16} = 51.7399407908695$$
$$x_{17} = 76.9040953473809$$
$$x_{18} = -26.5171686179843$$
$$x_{19} = 7.25024830711031$$
$$x_{20} = 95.7664129259896$$
$$x_{21} = 70.6151463420358$$
$$x_{22} = 64.3250751965547$$
$$x_{23} = -7.25024830711031$$
$$x_{24} = -95.7664129259896$$
$$x_{25} = 89.4795700005049$$
$$x_{26} = -76.9040953473809$$
$$x_{27} = -70.6151463420358$$
$$x_{28} = 13.7893118576574$$
$$x_{29} = -20.1774438696657$$
$$x_{30} = -83.1921757248865$$
Puntos máximos de la función:
$$x_{30} = 10.5531104299019$$
$$x_{30} = -29.6782238599607$$
$$x_{30} = 42.2938264412084$$
$$x_{30} = -61.1795112699548$$
$$x_{30} = -42.2938264412084$$
$$x_{30} = 54.8870259692204$$
$$x_{30} = -80.0482313681549$$
$$x_{30} = 98.909660402511$$
$$x_{30} = -3.79022237829253$$
$$x_{30} = -23.3510066366273$$
$$x_{30} = -73.7597432512514$$
$$x_{30} = 92.6230533845309$$
$$x_{30} = 16.9925901138555$$
$$x_{30} = -67.4702705534315$$
$$x_{30} = 73.7597432512514$$
$$x_{30} = -92.6230533845309$$
$$x_{30} = 67.4702705534315$$
$$x_{30} = -54.8870259692204$$
$$x_{30} = 35.9902726647882$$
$$x_{30} = 29.6782238599607$$
$$x_{30} = 61.1795112699548$$
$$x_{30} = 48.5921497153139$$
$$x_{30} = -16.9925901138555$$
$$x_{30} = 23.3510066366273$$
$$x_{30} = -10.5531104299019$$
$$x_{30} = 86.335949286752$$
$$x_{30} = 3.79022237829253$$
$$x_{30} = 80.0482313681549$$
$$x_{30} = -35.9902726647882$$
$$x_{30} = -98.909660402511$$
$$x_{30} = -48.5921497153139$$
$$x_{30} = -86.335949286752$$
Decrece en los intervalos
$$\left[95.7664129259896, \infty\right)$$
Crece en los intervalos
$$\left(-\infty, -95.7664129259896\right]$$