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 derivadaxcos(x)−x2sin(x)=0Resolvermos esta ecuaciónRaíces de esta ecuación
x1=17.2207552719308x2=−80.0981286289451x3=−83.2401924707234x4=98.9500628243319x5=−45.5311340139913x6=−86.3822220347287x7=7.72525183693771x8=−394.267341680887x9=−4.49340945790906x10=4.49340945790906x11=108.375719651675x12=39.2444323611642x13=−70.6716857116195x14=10.9041216594289x15=−42.3879135681319x16=80.0981286289451x17=89.5242209304172x18=−48.6741442319544x19=14.0661939128315x20=−36.1006222443756x21=−95.8081387868617x22=64.3871195905574x23=61.2447302603744x24=−54.9596782878889x25=76.9560263103312x26=−76.9560263103312x27=−98.9500628243319x28=−7.72525183693771x29=−20.3713029592876x30=−39.2444323611642x31=−14.0661939128315x32=−32.9563890398225x33=54.9596782878889x34=73.8138806006806x35=26.6660542588127x36=−26.6660542588127x37=−61.2447302603744x38=−67.5294347771441x39=29.811598790893x40=51.8169824872797x41=23.519452498689x42=−58.1022547544956x43=67.5294347771441x44=−10.9041216594289x45=−89.5242209304172x46=86.3822220347287x47=−23.519452498689x48=−17.2207552719308x49=−4355.81798462425x50=58.1022547544956x51=−92.6661922776228x52=−29.811598790893x53=92.6661922776228x54=−64.3871195905574x55=32.9563890398225x56=20.3713029592876x57=48.6741442319544x58=45.5311340139913x59=36.1006222443756x60=70.6716857116195x61=83.2401924707234x62=95.8081387868617x63=−73.8138806006806x64=42.3879135681319x65=−51.8169824872797Signos de extremos en los puntos:
(17.22075527193077, -0.0579718023461539)
(-80.09812862894512, -0.012483713321779)
(-83.2401924707234, 0.0120125604820527)
(98.95006282433188, -0.010105591736504)
(-45.53113401399128, 0.0219576982284824)
(-86.38222203472871, -0.0115756804584678)
(7.725251836937707, 0.128374553525899)
(-394.26734168088706, -0.00253634191261283)
(-4.493409457909064, -0.217233628211222)
(4.493409457909064, -0.217233628211222)
(108.37571965167469, 0.00922676625078197)
(39.24443236116419, 0.0254730530928808)
(-70.6716857116195, 0.0141485220648664)
(10.904121659428899, -0.0913252028230577)
(-42.38791356813192, -0.0235850682290164)
(80.09812862894512, -0.012483713321779)
(89.52422093041719, 0.0111694646341736)
(-48.674144231954386, -0.0205404540417537)
(14.066193912831473, 0.0709134594504622)
(-36.10062224437561, -0.0276897323011492)
(-95.8081387868617, 0.0104369581345658)
(64.38711959055742, 0.0155291838074613)
(61.2447302603744, -0.0163257593209978)
(-54.959678287888934, -0.0181921463218031)
(76.95602631033118, 0.0129933369870427)
(-76.95602631033118, 0.0129933369870427)
(-98.95006282433188, -0.010105591736504)
(-7.725251836937707, 0.128374553525899)
(-20.37130295928756, 0.0490296240140742)
(-39.24443236116419, 0.0254730530928808)
(-14.066193912831473, 0.0709134594504622)
(-32.956389039822476, 0.0303291711863103)
(54.959678287888934, -0.0181921463218031)
(73.81388060068065, -0.01354634434514)
(26.666054258812675, 0.0374745199939312)
(-26.666054258812675, 0.0374745199939312)
(-61.2447302603744, -0.0163257593209978)
(-67.52943477714412, -0.0148067339465492)
(29.81159879089296, -0.0335251350213988)
(51.81698248727967, 0.019295099487588)
(23.519452498689006, -0.0424796169776126)
(-58.10225475449559, 0.0172084874716279)
(67.52943477714412, -0.0148067339465492)
(-10.904121659428899, -0.0913252028230577)
(-89.52422093041719, 0.0111694646341736)
(86.38222203472871, -0.0115756804584678)
(-23.519452498689006, -0.0424796169776126)
(-17.22075527193077, -0.0579718023461539)
(-4355.817984624248, 0.000229577998248987)
(58.10225475449559, 0.0172084874716279)
(-92.66619227762284, -0.0107907938495342)
(-29.81159879089296, -0.0335251350213988)
(92.66619227762284, -0.0107907938495342)
(-64.38711959055742, 0.0155291838074613)
(32.956389039822476, 0.0303291711863103)
(20.37130295928756, 0.0490296240140742)
(48.674144231954386, -0.0205404540417537)
(45.53113401399128, 0.0219576982284824)
(36.10062224437561, -0.0276897323011492)
(70.6716857116195, 0.0141485220648664)
(83.2401924707234, 0.0120125604820527)
(95.8081387868617, 0.0104369581345658)
(-73.81388060068065, -0.01354634434514)
(42.38791356813192, -0.0235850682290164)
(-51.81698248727967, 0.019295099487588)
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=17.2207552719308x2=−80.0981286289451x3=98.9500628243319x4=−86.3822220347287x5=−394.267341680887x6=−4.49340945790906x7=4.49340945790906x8=10.9041216594289x9=−42.3879135681319x10=80.0981286289451x11=−48.6741442319544x12=−36.1006222443756x13=61.2447302603744x14=−54.9596782878889x15=−98.9500628243319x16=54.9596782878889x17=73.8138806006806x18=−61.2447302603744x19=−67.5294347771441x20=29.811598790893x21=23.519452498689x22=67.5294347771441x23=−10.9041216594289x24=86.3822220347287x25=−23.519452498689x26=−17.2207552719308x27=−92.6661922776228x28=−29.811598790893x29=92.6661922776228x30=48.6741442319544x31=36.1006222443756x32=−73.8138806006806x33=42.3879135681319Puntos máximos de la función:
x33=−83.2401924707234x33=−45.5311340139913x33=7.72525183693771x33=108.375719651675x33=39.2444323611642x33=−70.6716857116195x33=89.5242209304172x33=14.0661939128315x33=−95.8081387868617x33=64.3871195905574x33=76.9560263103312x33=−76.9560263103312x33=−7.72525183693771x33=−20.3713029592876x33=−39.2444323611642x33=−14.0661939128315x33=−32.9563890398225x33=26.6660542588127x33=−26.6660542588127x33=51.8169824872797x33=−58.1022547544956x33=−89.5242209304172x33=−4355.81798462425x33=58.1022547544956x33=−64.3871195905574x33=32.9563890398225x33=20.3713029592876x33=45.5311340139913x33=70.6716857116195x33=83.2401924707234x33=95.8081387868617x33=−51.8169824872797Decrece en los intervalos
[98.9500628243319,∞)Crece en los intervalos
(−∞,−394.267341680887]