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−4x3sin(x)+12x2cos(x)=0Resolvermos esta ecuaciónRaíces de esta ecuación
x1=−9.72402747617551x2=−72.2981021067071x3=−87.9986725257711x4=−84.8583399660622x5=84.8583399660622x6=81.7181040853573x7=56.6016202331048x8=40.913898225293x9=3.80876221919969x10=0x11=−75.4379705139506x12=−97.4201569811411x13=97.4201569811411x14=22.12591435735x15=100.560788770886x16=−15.8945130636842x17=−66.0188560490172x18=66.0188560490172x19=−22.12591435735x20=69.1583898858035x21=−28.3796522911214x22=−34.6438990396267x23=−78.5779764426249x24=37.7783560989567x25=−25.2509941253717x26=−59.7404355133729x27=12.7966483902814x28=−62.8795272030449x29=−6.70395577578075x30=−1.19245882933643x31=91.1390917936668x32=47.1873806732917x33=44.0502961191214x34=1.19245882933643x35=−56.6016202331048x36=15.8945130636842x37=−53.4631297645908x38=62.8795272030449x39=−40.913898225293x40=19.0061082873963x41=6.70395577578075x42=78.5779764426249x43=72.2981021067071x44=−31.510845756676x45=31.510845756676x46=−44.0502961191214x47=−50.325024483292x48=75.4379705139506x49=50.325024483292x50=59.7404355133729x51=−94.2795891235637x52=−19.0061082873963x53=−100.560788770886x54=−37.7783560989567x55=−3.80876221919969x56=87.9986725257711x57=9.72402747617551x58=53.4631297645908x59=−12.7966483902814x60=−81.7181040853573x61=25.2509941253717x62=28.3796522911214x63=34.6438990396267x64=−91.1390917936668x65=94.2795891235637x66=−69.1583898858035x67=−47.1873806732917Signos de extremos en los puntos:
(-9.72402747617551, 3514.43550360095)
(-72.29810210670713, 1510313.53335791)
(-87.99867252577111, -2724182.04559702)
(-84.85833996606219, 2442712.51279198)
(84.85833996606219, -2442712.51279198)
(81.71810408535728, 2181335.04597451)
(56.60162023310481, 724331.58435522)
(40.91389822529297, -273217.30613698)
(3.808762219199689, -173.620051816331)
(0, 0)
(-75.43797051395065, -1715879.70709431)
(-97.42015698114113, 3696584.54759441)
(97.42015698114113, -3696584.54759441)
(22.125914357349984, -42934.6461855845)
(100.56078877088648, 4065863.85192867)
(-15.894513063684203, 15783.3987495175)
(-66.01885604901719, 1149783.42283034)
(66.01885604901719, -1149783.42283034)
(-22.125914357349984, 42934.6461855845)
(69.15838988580347, 1321862.8222492)
(-28.37965229112142, 90921.8253044151)
(-34.64389903962671, 165698.289727675)
(-78.57797644262494, 1939305.49434903)
(37.77835609895673, 214992.901302738)
(-25.25099412537165, -63951.6564937612)
(-59.74043551337287, 851761.955001316)
(12.796648390281426, 8160.76026338815)
(-62.87952720304487, -993331.184104639)
(-6.703955775780748, -1100.06136834542)
(-1.1924588293364287, -2.50529519287726)
(91.13909179366682, -3026487.7951639)
(47.18738067329166, -419432.109446505)
(44.05029611912139, 341115.657892607)
(1.1924588293364287, 2.50529519287726)
(-56.60162023310481, -724331.58435522)
(15.894513063684203, -15783.3987495175)
(-53.463129764590846, 610295.920879583)
(62.87952720304487, 993331.184104639)
(-40.91389822529297, 273217.30613698)
(19.006108287396344, 27126.6224448194)
(6.703955775780748, 1100.06136834542)
(78.57797644262494, -1939305.49434903)
(72.29810210670713, -1510313.53335791)
(-31.51084575667604, -124589.316590486)
(31.51084575667604, 124589.316590486)
(-44.05029611912139, -341115.657892607)
(-50.32502448329199, -508910.813128767)
(75.43797051395065, 1715879.70709431)
(50.32502448329199, 508910.813128767)
(59.74043551337287, -851761.955001316)
(-94.27958912356374, -3350373.91224916)
(-19.006108287396344, -27126.6224448194)
(-100.56078877088648, -4065863.85192867)
(-37.77835609895673, -214992.901302738)
(-3.808762219199689, 173.620051816331)
(87.99867252577111, 2724182.04559702)
(9.72402747617551, -3514.43550360095)
(53.463129764590846, -610295.920879583)
(-12.796648390281426, -8160.76026338815)
(-81.71810408535728, -2181335.04597451)
(25.25099412537165, 63951.6564937612)
(28.37965229112142, -90921.8253044151)
(34.64389903962671, -165698.289727675)
(-91.13909179366682, 3026487.7951639)
(94.27958912356374, 3350373.91224916)
(-69.15838988580347, -1321862.8222492)
(-47.18738067329166, 419432.109446505)
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=−87.9986725257711x2=84.8583399660622x3=40.913898225293x4=3.80876221919969x5=−75.4379705139506x6=97.4201569811411x7=22.12591435735x8=66.0188560490172x9=−25.2509941253717x10=−62.8795272030449x11=−6.70395577578075x12=−1.19245882933643x13=91.1390917936668x14=47.1873806732917x15=−56.6016202331048x16=15.8945130636842x17=78.5779764426249x18=72.2981021067071x19=−31.510845756676x20=−44.0502961191214x21=−50.325024483292x22=59.7404355133729x23=−94.2795891235637x24=−19.0061082873963x25=−100.560788770886x26=−37.7783560989567x27=9.72402747617551x28=53.4631297645908x29=−12.7966483902814x30=−81.7181040853573x31=28.3796522911214x32=34.6438990396267x33=−69.1583898858035Puntos máximos de la función:
x33=−9.72402747617551x33=−72.2981021067071x33=−84.8583399660622x33=81.7181040853573x33=56.6016202331048x33=−97.4201569811411x33=100.560788770886x33=−15.8945130636842x33=−66.0188560490172x33=−22.12591435735x33=69.1583898858035x33=−28.3796522911214x33=−34.6438990396267x33=−78.5779764426249x33=37.7783560989567x33=−59.7404355133729x33=12.7966483902814x33=44.0502961191214x33=1.19245882933643x33=−53.4631297645908x33=62.8795272030449x33=−40.913898225293x33=19.0061082873963x33=6.70395577578075x33=31.510845756676x33=75.4379705139506x33=50.325024483292x33=−3.80876221919969x33=87.9986725257711x33=25.2509941253717x33=−91.1390917936668x33=94.2795891235637x33=−47.1873806732917Decrece en los intervalos
[97.4201569811411,∞)Crece en los intervalos
(−∞,−100.560788770886]