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−4xsin(x)+4cos(x)=0Resolvermos esta ecuaciónRaíces de esta ecuación
x1=6.43729817917195x2=81.6936492356017x3=9.52933440536196x4=−12.6452872238566x5=0.86033358901938x6=15.7712848748159x7=65.9885986984904x8=62.8477631944545x9=−97.3996388790738x10=−65.9885986984904x11=−25.1724463266467x12=59.7070073053355x13=75.4114834888481x14=−53.4257904773947x15=25.1724463266467x16=50.2853663377737x17=−40.8651703304881x18=−28.309642854452x19=−72.270467060309x20=−78.5525459842429x21=−87.9759605524932x22=12.6452872238566x23=3.42561845948173x24=−6.43729817917195x25=47.145097736761x26=56.5663442798215x27=97.3996388790738x28=−94.2583883450399x29=−56.5663442798215x30=−3.42561845948173x31=100.540910786842x32=44.0050179208308x33=−15.7712848748159x34=72.270467060309x35=−34.5864242152889x36=−22.0364967279386x37=−91.1171613944647x38=−31.4477146375462x39=−59.7070073053355x40=−9.52933440536196x41=40.8651703304881x42=34.5864242152889x43=−37.7256128277765x44=−50.2853663377737x45=−47.145097736761x46=53.4257904773947x47=−69.1295029738953x48=−44.0050179208308x49=−84.8347887180423x50=22.0364967279386x51=69.1295029738953x52=−147.661626855354x53=−62.8477631944545x54=78.5525459842429x55=−116.247530303932x56=28.309642854452x57=31.4477146375462x58=91.1171613944647x59=−75.4114834888481x60=18.90240995686x61=84.8347887180423x62=37.7256128277765x63=87.9759605524932x64=94.2583883450399x65=−81.6936492356017x66=−100.540910786842x67=−18.90240995686x68=−0.86033358901938Signos de extremos en los puntos:
(6.437298179171947, 25.4440157793354)
(81.69364923560168, 326.750117986098)
(9.529334405361963, -37.9091770379192)
(-12.645287223856643, -50.4237251915707)
(0.8603335890193797, 2.24438535276418)
(15.771284874815882, -62.9587078485349)
(65.98859869849039, -263.924091747167)
(62.84776319445445, 251.359235888618)
(-97.39963887907376, 389.578023182494)
(-65.98859869849039, 263.924091747167)
(-25.172446326646664, -100.610427271486)
(59.70700730533546, -238.794539361063)
(75.41148348884815, 301.619416292808)
(-53.42579047739466, 213.665736639585)
(25.172446326646664, 100.610427271486)
(50.28536633777365, 201.101704141589)
(-40.86517033048807, 163.41176185807)
(-28.30964285445201, 113.167990156377)
(-72.27046706030896, 289.054198392998)
(-78.55254598424293, 314.184726366937)
(-87.97596055249322, -351.881110929699)
(12.645287223856643, 50.4237251915707)
(3.4256184594817283, -13.1534855823636)
(-6.437298179171947, -25.4440157793354)
(47.14509773676103, -188.537983030168)
(56.56634427982152, 226.230028691505)
(97.39963887907376, -389.578023182494)
(-94.25838834503986, -377.012336900435)
(-56.56634427982152, -226.230028691505)
(-3.4256184594817283, 13.1534855823636)
(100.54091078684232, 402.143752223304)
(44.005017920830845, 175.974639916426)
(-15.771284874815882, 62.9587078485349)
(72.27046706030896, -289.054198392998)
(-34.58642421528892, 138.287906934354)
(-22.036496727938566, 88.0553683166339)
(-91.11716139446474, 364.446697798588)
(-31.447714637546234, -125.727309114138)
(-59.70700730533546, 238.794539361063)
(-9.529334405361963, 37.9091770379192)
(40.86517033048807, -163.41176185807)
(34.58642421528892, -138.287906934354)
(-37.7256128277765, -150.84946485124)
(-50.28536633777365, -201.101704141589)
(-47.14509773676103, 188.537983030168)
(53.42579047739466, -213.665736639585)
(-69.12950297389526, -276.489085227687)
(-44.005017920830845, -175.974639916426)
(-84.83478871804229, 339.315582094627)
(22.036496727938566, -88.0553683166339)
(69.12950297389526, 276.489085227687)
(-147.66162685535437, 590.632963406968)
(-62.84776319445445, -251.359235888618)
(78.55254598424293, -314.184726366937)
(-116.2475303039321, 464.972917503947)
(28.30964285445201, -113.167990156377)
(31.447714637546234, 125.727309114138)
(91.11716139446474, -364.446697798588)
(-75.41148348884815, -301.619416292808)
(18.902409956860023, 75.5040547918761)
(84.83478871804229, -339.315582094627)
(37.7256128277765, 150.84946485124)
(87.97596055249322, 351.881110929699)
(94.25838834503986, 377.012336900435)
(-81.69364923560168, -326.750117986098)
(-100.54091078684232, -402.143752223304)
(-18.902409956860023, -75.5040547918761)
(-0.8603335890193797, -2.24438535276418)
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=9.52933440536196x2=−12.6452872238566x3=15.7712848748159x4=65.9885986984904x5=−25.1724463266467x6=59.7070073053355x7=−87.9759605524932x8=3.42561845948173x9=−6.43729817917195x10=47.145097736761x11=97.3996388790738x12=−94.2583883450399x13=−56.5663442798215x14=72.270467060309x15=−31.4477146375462x16=40.8651703304881x17=34.5864242152889x18=−37.7256128277765x19=−50.2853663377737x20=53.4257904773947x21=−69.1295029738953x22=−44.0050179208308x23=22.0364967279386x24=−62.8477631944545x25=78.5525459842429x26=28.309642854452x27=91.1171613944647x28=−75.4114834888481x29=84.8347887180423x30=−81.6936492356017x31=−100.540910786842x32=−18.90240995686x33=−0.86033358901938Puntos máximos de la función:
x33=6.43729817917195x33=81.6936492356017x33=0.86033358901938x33=62.8477631944545x33=−97.3996388790738x33=−65.9885986984904x33=75.4114834888481x33=−53.4257904773947x33=25.1724463266467x33=50.2853663377737x33=−40.8651703304881x33=−28.309642854452x33=−72.270467060309x33=−78.5525459842429x33=12.6452872238566x33=56.5663442798215x33=−3.42561845948173x33=100.540910786842x33=44.0050179208308x33=−15.7712848748159x33=−34.5864242152889x33=−22.0364967279386x33=−91.1171613944647x33=−59.7070073053355x33=−9.52933440536196x33=−47.145097736761x33=−84.8347887180423x33=69.1295029738953x33=−147.661626855354x33=−116.247530303932x33=31.4477146375462x33=18.90240995686x33=37.7256128277765x33=87.9759605524932x33=94.2583883450399Decrece en los intervalos
[97.3996388790738,∞)Crece en los intervalos
(−∞,−100.540910786842]