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 derivada−x3sin(x)−x43cos(x)=0Resolvermos esta ecuaciónRaíces de esta ecuación
x1=12.327655521099x2=−100.50112336357x3=−47.0602278498565x4=75.3584349525985x5=−84.7876338830228x6=50.2057993706114x7=37.6195344424891x8=56.4956161262601x9=78.50161915521x10=94.2159486198017x11=72.2151123545007x12=−380.124819103717x13=5.80628149104622x14=100.50112336357x15=18.6904032530853x16=−72.2151123545007x17=−62.7841065943838x18=−81.6446809310296x19=91.0732583460488x20=97.3585680793661x21=−31.3204337466541x22=40.7672484166364x23=−25.0133755606323x24=−40.7672484166364x25=65.9279728888237x26=31.3204337466541x27=−34.4707075119921x28=−65.9279728888237x29=21.8547311042253x30=−91.0732583460488x31=−87.9304896708771x32=−59.6400009696211x33=−9.10654133164946x34=87.9304896708771x35=34.4707075119921x36=28.1682308860662x37=69.0716324888295x38=−94.2159486198017x39=−37.6195344424891x40=518.35700038984x41=47.0602278498565x42=59.6400009696211x43=81.6446809310296x44=53.3509027906022x45=−2.20452539445172x46=−18.6904032530853x47=−15.5169830019484x48=−97.3585680793661x49=15.5169830019484x50=43.9140879217563x51=−43.9140879217563x52=62.7841065943838x53=−78.50161915521x54=−50.2057993706114x55=9.10654133164946x56=−28.1682308860662x57=−12.327655521099x58=−75.3584349525985x59=−1083.84669757642x60=2.20452539445172x61=84.7876338830228x62=−5.80628149104622x63=−56.4956161262601x64=−53.3509027906022x65=−103.643620306534x66=25.0133755606323x67=−69.0716324888295x68=−21.8547311042253Signos de extremos en los puntos:
(12.327655521098961, 0.000518638886803666)
(-100.50112336356959, -9.84677125634237e-7)
(-47.06022784985651, 9.5754074775838e-6)
(75.35843495259849, 2.33485826727833e-6)
(-84.7876338830228, 1.63957304942886e-6)
(50.20579937061139, 7.88795433540522e-6)
(37.619534442489126, 1.87233345638677e-5)
(56.49561612626008, 5.53788980086548e-6)
(78.50161915520997, -2.0656049051152e-6)
(94.21594861980165, 1.19510667228868e-6)
(72.21511235450072, -2.65302474093483e-6)
(-380.1248191037165, 1.82057173454409e-8)
(5.8062814910462155, 0.00453862470500485)
(100.50112336356959, 9.84677125634237e-7)
(18.690403253085307, 0.000151223874462241)
(-72.21511235450072, 2.65302474093483e-6)
(-62.78410659438384, -4.03604146547336e-6)
(-81.64468093102955, -1.83621412894209e-6)
(91.07325834604883, -1.32309760125654e-6)
(97.3585680793661, -1.08310705206369e-6)
(-31.320433746654114, -3.23991444144119e-5)
(40.767248416636356, -1.47195001853466e-5)
(-25.01337556063232, -6.34427155787386e-5)
(-40.767248416636356, 1.47195001853466e-5)
(65.92797288882375, -3.48611464323845e-6)
(31.320433746654114, 3.23991444144119e-5)
(-34.47070751199214, 2.43226487730105e-5)
(-65.92797288882375, 3.48611464323845e-6)
(21.854731104225348, -9.49095579677938e-5)
(-91.07325834604883, 1.32309760125654e-6)
(-87.93048967087708, -1.47003916834536e-6)
(-59.640000969621056, 4.70802030061175e-6)
(-9.106541331649463, 0.00125766965231332)
(87.93048967087708, 1.47003916834536e-6)
(34.47070751199214, -2.43226487730105e-5)
(28.1682308860662, -4.44909904084811e-5)
(69.07163248882952, 3.03173745311126e-6)
(-94.21594861980165, -1.19510667228868e-6)
(-37.619534442489126, -1.87233345638677e-5)
(518.35700038984, -7.17969214279648e-9)
(47.06022784985651, -9.5754074775838e-6)
(59.640000969621056, -4.70802030061175e-6)
(81.64468093102955, 1.83621412894209e-6)
(53.350902790602206, -6.57489996749211e-6)
(-2.2045253944517174, 0.0552699707829989)
(-18.690403253085307, -0.000151223874462241)
(-15.516983001948434, 0.000262790351635489)
(-97.3585680793661, 1.08310705206369e-6)
(15.516983001948434, -0.000262790351635489)
(43.914087921756334, 1.17808692820516e-5)
(-43.914087921756334, -1.17808692820516e-5)
(62.78410659438384, 4.03604146547336e-6)
(-78.50161915520997, 2.0656049051152e-6)
(-50.20579937061139, -7.88795433540522e-6)
(9.106541331649463, -0.00125766965231332)
(-28.1682308860662, 4.44909904084811e-5)
(-12.327655521098961, -0.000518638886803666)
(-75.35843495259849, -2.33485826727833e-6)
(-1083.846697576425, 7.85406986804821e-10)
(2.2045253944517174, -0.0552699707829989)
(84.7876338830228, -1.63957304942886e-6)
(-5.8062814910462155, -0.00453862470500485)
(-56.49561612626008, -5.53788980086548e-6)
(-53.350902790602206, 6.57489996749211e-6)
(-103.64362030653376, 8.97822364178806e-7)
(25.01337556063232, 6.34427155787386e-5)
(-69.07163248882952, -3.03173745311126e-6)
(-21.854731104225348, 9.49095579677938e-5)
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=−100.50112336357x2=78.50161915521x3=72.2151123545007x4=−62.7841065943838x5=−81.6446809310296x6=91.0732583460488x7=97.3585680793661x8=−31.3204337466541x9=40.7672484166364x10=−25.0133755606323x11=65.9279728888237x12=21.8547311042253x13=−87.9304896708771x14=34.4707075119921x15=28.1682308860662x16=−94.2159486198017x17=−37.6195344424891x18=518.35700038984x19=47.0602278498565x20=59.6400009696211x21=53.3509027906022x22=−18.6904032530853x23=15.5169830019484x24=−43.9140879217563x25=−50.2057993706114x26=9.10654133164946x27=−12.327655521099x28=−75.3584349525985x29=2.20452539445172x30=84.7876338830228x31=−5.80628149104622x32=−56.4956161262601x33=−69.0716324888295Puntos máximos de la función:
x33=12.327655521099x33=−47.0602278498565x33=75.3584349525985x33=−84.7876338830228x33=50.2057993706114x33=37.6195344424891x33=56.4956161262601x33=94.2159486198017x33=−380.124819103717x33=5.80628149104622x33=100.50112336357x33=18.6904032530853x33=−72.2151123545007x33=−40.7672484166364x33=31.3204337466541x33=−34.4707075119921x33=−65.9279728888237x33=−91.0732583460488x33=−59.6400009696211x33=−9.10654133164946x33=87.9304896708771x33=69.0716324888295x33=81.6446809310296x33=−2.20452539445172x33=−15.5169830019484x33=−97.3585680793661x33=43.9140879217563x33=62.7841065943838x33=−78.50161915521x33=−28.1682308860662x33=−1083.84669757642x33=−53.3509027906022x33=−103.643620306534x33=25.0133755606323x33=−21.8547311042253Decrece en los intervalos
[518.35700038984,∞)Crece en los intervalos
(−∞,−100.50112336357]