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−xsin(x)+cos(x)=0Resolvermos esta ecuaciónRaíces de esta ecuación
x1=40.8651703304881x2=−78.5525459842429x3=−53.4257904773947x4=−50.2853663377737x5=15.7712848748159x6=−44.0050179208308x7=87.9759605524932x8=59.7070073053355x9=−116.247530303932x10=−47.145097736761x11=53.4257904773947x12=−22.0364967279386x13=50.2853663377737x14=69.1295029738953x15=65.9885986984904x16=0.86033358901938x17=−0.86033358901938x18=12.6452872238566x19=−34.5864242152889x20=25.1724463266467x21=−28.309642854452x22=62.8477631944545x23=−87.9759605524932x24=−40.8651703304881x25=−147.661626855354x26=44.0050179208308x27=−59.7070073053355x28=3.42561845948173x29=56.5663442798215x30=−81.6936492356017x31=22.0364967279386x32=−3.42561845948173x33=9.52933440536196x34=72.270467060309x35=81.6936492356017x36=−75.4114834888481x37=37.7256128277765x38=75.4114834888481x39=6.43729817917195x40=−91.1171613944647x41=−84.8347887180423x42=−9.52933440536196x43=−6.43729817917195x44=−18.90240995686x45=−100.540910786842x46=−25.1724463266467x47=18.90240995686x48=28.309642854452x49=−69.1295029738953x50=84.8347887180423x51=91.1171613944647x52=−62.8477631944545x53=34.5864242152889x54=−94.2583883450399x55=−56.5663442798215x56=94.2583883450399x57=47.145097736761x58=97.3996388790738x59=31.4477146375462x60=−31.4477146375462x61=−37.7256128277765x62=78.5525459842429x63=−12.6452872238566x64=−72.270467060309x65=−65.9885986984904x66=−15.7712848748159x67=−97.3996388790738x68=100.540910786842Signos de extremos en los puntos:
(40.86517033048807, -40.8529404645174)
(-78.55254598424293, 78.5461815917343)
(-53.42579047739466, 53.4164341598961)
(-50.28536633777365, -50.2754260353972)
(15.771284874815882, -15.7396769621337)
(-44.005017920830845, -43.9936599791065)
(87.97596055249322, 87.9702777324248)
(59.70700730533546, -59.6986348402658)
(-116.2475303039321, 116.243229375987)
(-47.14509773676103, 47.1344957575419)
(53.42579047739466, -53.4164341598961)
(-22.036496727938566, 22.0138420791585)
(50.28536633777365, 50.2754260353972)
(69.12950297389526, 69.1222713069218)
(65.98859869849039, -65.9810229367917)
(0.8603335890193797, 0.561096338191045)
(-0.8603335890193797, -0.561096338191045)
(12.645287223856643, 12.6059312978927)
(-34.58642421528892, 34.5719767335884)
(25.172446326646664, 25.1526068178715)
(-28.30964285445201, 28.2919975390943)
(62.84776319445445, 62.8398089721545)
(-87.97596055249322, -87.9702777324248)
(-40.86517033048807, 40.8529404645174)
(-147.66162685535437, 147.658240851742)
(44.005017920830845, 43.9936599791065)
(-59.70700730533546, 59.6986348402658)
(3.4256184594817283, -3.2883713955909)
(56.56634427982152, 56.5575071728762)
(-81.69364923560168, -81.6875294965246)
(22.036496727938566, -22.0138420791585)
(-3.4256184594817283, 3.2883713955909)
(9.529334405361963, -9.47729425947979)
(72.27046706030896, -72.2635495982494)
(81.69364923560168, 81.6875294965246)
(-75.41148348884815, -75.4048540732019)
(37.7256128277765, 37.71236621281)
(75.41148348884815, 75.4048540732019)
(6.437298179171947, 6.36100394483385)
(-91.11716139446474, 91.1116744496469)
(-84.83478871804229, 84.8288955236568)
(-9.529334405361963, 9.47729425947979)
(-6.437298179171947, -6.36100394483385)
(-18.902409956860023, -18.876013697969)
(-100.54091078684232, -100.535938055826)
(-25.172446326646664, -25.1526068178715)
(18.902409956860023, 18.876013697969)
(28.30964285445201, -28.2919975390943)
(-69.12950297389526, -69.1222713069218)
(84.83478871804229, -84.8288955236568)
(91.11716139446474, -91.1116744496469)
(-62.84776319445445, -62.8398089721545)
(34.58642421528892, -34.5719767335884)
(-94.25838834503986, -94.2530842251087)
(-56.56634427982152, -56.5575071728762)
(94.25838834503986, 94.2530842251087)
(47.14509773676103, -47.1344957575419)
(97.39963887907376, -97.3945057956234)
(31.447714637546234, 31.4318272785346)
(-31.447714637546234, -31.4318272785346)
(-37.7256128277765, -37.71236621281)
(78.55254598424293, -78.5461815917343)
(-12.645287223856643, -12.6059312978927)
(-72.27046706030896, 72.2635495982494)
(-65.98859869849039, 65.9810229367917)
(-15.771284874815882, 15.7396769621337)
(-97.39963887907376, 97.3945057956234)
(100.54091078684232, 100.535938055826)
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=40.8651703304881x2=−50.2853663377737x3=15.7712848748159x4=−44.0050179208308x5=59.7070073053355x6=53.4257904773947x7=65.9885986984904x8=−0.86033358901938x9=−87.9759605524932x10=3.42561845948173x11=−81.6936492356017x12=22.0364967279386x13=9.52933440536196x14=72.270467060309x15=−75.4114834888481x16=−6.43729817917195x17=−18.90240995686x18=−100.540910786842x19=−25.1724463266467x20=28.309642854452x21=−69.1295029738953x22=84.8347887180423x23=91.1171613944647x24=−62.8477631944545x25=34.5864242152889x26=−94.2583883450399x27=−56.5663442798215x28=47.145097736761x29=97.3996388790738x30=−31.4477146375462x31=−37.7256128277765x32=78.5525459842429x33=−12.6452872238566Puntos máximos de la función:
x33=−78.5525459842429x33=−53.4257904773947x33=87.9759605524932x33=−116.247530303932x33=−47.145097736761x33=−22.0364967279386x33=50.2853663377737x33=69.1295029738953x33=0.86033358901938x33=12.6452872238566x33=−34.5864242152889x33=25.1724463266467x33=−28.309642854452x33=62.8477631944545x33=−40.8651703304881x33=−147.661626855354x33=44.0050179208308x33=−59.7070073053355x33=56.5663442798215x33=−3.42561845948173x33=81.6936492356017x33=37.7256128277765x33=75.4114834888481x33=6.43729817917195x33=−91.1171613944647x33=−84.8347887180423x33=−9.52933440536196x33=18.90240995686x33=94.2583883450399x33=31.4477146375462x33=−72.270467060309x33=−65.9885986984904x33=−15.7712848748159x33=−97.3996388790738x33=100.540910786842Decrece en los intervalos
[97.3996388790738,∞)Crece en los intervalos
(−∞,−100.540910786842]