Para hallar los extremos hay que resolver la ecuación
dxdf(x)=0(la derivada es igual a cero),
y las raíces de esta ecuación serán los extremos de esta función:
dxdf(x)=primera derivadax3cos(x)−x43sin(x)=0Resolvermos esta ecuaciónRaíces de esta ecuación
x1=−13.924969952549x2=−95.7872667660245x3=61.2120859995403x4=13.924969952549x5=−26.591193287969x6=−23.4346216921802x7=−45.4872362867621x8=−108.357267428671x9=−98.9298533613919x10=29.7446115259422x11=76.930043294192x12=42.3407653325706x13=−54.9233040395155x14=−32.8957773192946x15=54.9233040395155x16=−186.908713650658x17=23.4346216921802x18=−64.3560674689022x19=67.4998267230665x20=39.1935138550425x21=17.1051395364267x22=−92.6446127847888x23=10.7227710626892x24=86.359073259985x25=−51.7784042739041x26=70.6433933906731x27=−76.930043294192x28=89.5018843244389x29=48.6330777853047x30=−36.0452782424582x31=83.2161702400252x32=−67.4998267230665x33=80.0731644462726x34=−89.5018843244389x35=32.8957773192946x36=3215.41914794509x37=−48.6330777853047x38=98.9298533613919x39=−10.7227710626892x40=26.591193287969x41=−42.3407653325706x42=4.07814976485137x43=36.0452782424582x44=−86.359073259985x45=95.7872667660245x46=7.47219265966058x47=−58.0678462801751x48=−39.1935138550425x49=−20.2734415170608x50=−83.2161702400252x51=−73.7867920572034x52=−70.6433933906731x53=92.6446127847888x54=−17.1051395364267x55=64.3560674689022x56=20.2734415170608x57=45.4872362867621x58=−7.47219265966058x59=58.0678462801751x60=−61.2120859995403x61=−29.7446115259422x62=73.7867920572034x63=−4.07814976485137x64=−80.0731644462726x65=51.7784042739041Signos de extremos en los puntos:
(-13.92496995254897, 0.000362047304723488)
(-95.78726676602449, 1.1372704641271e-6)
(61.21208599954033, -4.35479288166118e-6)
(13.92496995254897, 0.000362047304723488)
(-26.59119328796898, 5.28494009082656e-5)
(-23.4346216921802, -7.70719574291125e-5)
(-45.48723628676209, 1.06020259212848e-5)
(-108.35726742867121, 7.85704936475449e-7)
(-98.9298533613919, -1.03232943885669e-6)
(29.744611525942226, -3.78074454700618e-5)
(76.93004329419203, 2.19473504875366e-6)
(42.34076533257061, -1.31412441116291e-5)
(-54.92330403951548, -6.02674942320184e-6)
(-32.89577731929462, 2.79757033726946e-5)
(54.92330403951548, -6.02674942320184e-6)
(-186.90871365065752, -1.53128285331065e-7)
(23.4346216921802, -7.70719574291125e-5)
(-64.35606746890217, 3.7476597286644e-6)
(67.49982672306646, -3.24835521431348e-6)
(39.193513855042454, 1.65610881918558e-5)
(17.105139536426744, -0.000196807350078387)
(-92.64461278478876, -1.25693237122389e-6)
(10.722771062689203, -0.00078111312666525)
(86.359073259985, -1.55172297524868e-6)
(-51.77840427390411, 7.1916125507828e-6)
(70.64339339067311, 2.83396240646379e-6)
(-76.93004329419203, 2.19473504875366e-6)
(89.50188432443886, 1.39398991793862e-6)
(48.63307778530466, -8.67720806398467e-6)
(-36.04527824245817, -2.12792275158681e-5)
(83.21617024002518, 1.73418247352317e-6)
(-67.49982672306646, -3.24835521431348e-6)
(80.07316444627257, -1.94641047170913e-6)
(-89.50188432443886, 1.39398991793862e-6)
(32.89577731929462, 2.79757033726946e-5)
(3215.41914794509, -3.00806370783767e-11)
(-48.63307778530466, -8.67720806398467e-6)
(98.9298533613919, -1.03232943885669e-6)
(-10.722771062689203, -0.00078111312666525)
(26.59119328796898, 5.28494009082656e-5)
(-42.34076533257061, -1.31412441116291e-5)
(4.078149764851372, -0.0118764951343876)
(36.04527824245817, -2.12792275158681e-5)
(-86.359073259985, -1.55172297524868e-6)
(95.78726676602449, 1.1372704641271e-6)
(7.472192659660579, 0.00222435242575847)
(-58.067846280175104, 5.1005149012716e-6)
(-39.193513855042454, 1.65610881918558e-5)
(-20.27344151706078, 0.000118717289027919)
(-83.21617024002518, 1.73418247352317e-6)
(-73.78679205720341, -2.48716990126569e-6)
(-70.64339339067311, 2.83396240646379e-6)
(92.64461278478876, -1.25693237122389e-6)
(-17.105139536426744, -0.000196807350078387)
(64.35606746890217, 3.7476597286644e-6)
(20.27344151706078, 0.000118717289027919)
(45.48723628676209, 1.06020259212848e-5)
(-7.472192659660579, 0.00222435242575847)
(58.067846280175104, 5.1005149012716e-6)
(-61.21208599954033, -4.35479288166118e-6)
(-29.744611525942226, -3.78074454700618e-5)
(73.78679205720341, -2.48716990126569e-6)
(-4.078149764851372, -0.0118764951343876)
(-80.07316444627257, -1.94641047170913e-6)
(51.77840427390411, 7.1916125507828e-6)
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:
x1=61.2120859995403x2=−23.4346216921802x3=−98.9298533613919x4=29.7446115259422x5=42.3407653325706x6=−54.9233040395155x7=54.9233040395155x8=−186.908713650658x9=23.4346216921802x10=67.4998267230665x11=17.1051395364267x12=−92.6446127847888x13=10.7227710626892x14=86.359073259985x15=48.6330777853047x16=−36.0452782424582x17=−67.4998267230665x18=80.0731644462726x19=3215.41914794509x20=−48.6330777853047x21=98.9298533613919x22=−10.7227710626892x23=−42.3407653325706x24=4.07814976485137x25=36.0452782424582x26=−86.359073259985x27=−73.7867920572034x28=92.6446127847888x29=−17.1051395364267x30=−61.2120859995403x31=−29.7446115259422x32=73.7867920572034x33=−4.07814976485137x34=−80.0731644462726Puntos máximos de la función:
x34=−13.924969952549x34=−95.7872667660245x34=13.924969952549x34=−26.591193287969x34=−45.4872362867621x34=−108.357267428671x34=76.930043294192x34=−32.8957773192946x34=−64.3560674689022x34=39.1935138550425x34=−51.7784042739041x34=70.6433933906731x34=−76.930043294192x34=89.5018843244389x34=83.2161702400252x34=−89.5018843244389x34=32.8957773192946x34=26.591193287969x34=95.7872667660245x34=7.47219265966058x34=−58.0678462801751x34=−39.1935138550425x34=−20.2734415170608x34=−83.2161702400252x34=−70.6433933906731x34=64.3560674689022x34=20.2734415170608x34=45.4872362867621x34=−7.47219265966058x34=58.0678462801751x34=51.7784042739041Decrece en los intervalos
[3215.41914794509,∞)Crece en los intervalos
(−∞,−186.908713650658]