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−xe−xcos(x)+sin(x)sin(x)=0Resolvermos esta ecuaciónRaíces de esta ecuación
x1=−15.707963267949x2=0x3=−91.1998699041465x4=81.6814089933346x5=−72.2566310325652x6=−34.9294771386704x7=50.2654824574367x8=69.5606259232977x9=−40.8417340899375x10=25.1327412287183x11=−65.9734457253857x12=−53.4070751110265x13=−59.6902604182061x14=74.5739798656666x15=−46.5524448088427x16=18.8495559215388x17=80.5118670544782x18=63.6359781723457x19=12.5663706143592x20=56.5486677646163x21=−21.9911485751286x22=6.28318530717959x23=−78.5398163397448x24=37.6991118430775x25=−96.2124947519558x26=21.9911485751286x27=−97.3893722612836x28=100.530964914873x29=−47.1238898038469x30=28.2743338823081x31=94.2477796076938x32=−40.8407044966673x33=−34.5575191894877x34=−28.2743338823081x35=−85.4121130834002x36=−90.260314866971x37=−34.9842404193317x38=−79.4606661258204x39=43.9822971502571x40=75.398223686155x41=62.8318530717959x42=−84.3813701398482x43=−3.14159265358979x44=68.7396225684591x45=87.9645943005142x46=−9.42477796076938x47=31.4159265358979x48=31.2527380956438Signos de extremos en los puntos:
(-15.707963267948966, -1.50701727539007e-7)
(0, -1)
(-91.19986990414654, -4.04303150065854e-40)
(81.68140899333463, -3.35903709639911e-36)
(-72.25663103256524, -4.16240046723054e-32)
(-34.92947713867037, -1.06047627266875e-14)
(50.26548245743669, -1.47903461596179e-22)
(69.56062592329772, -8.45545260626203e-28)
(-40.84173408993747, -1.83280728040168e-18)
(25.132741228718345, -1.21615567094093e-11)
(-65.97344572538566, -2.22893071715432e-29)
(-53.40707511102649, -6.39148810034623e-24)
(-59.69026041820607, -1.19357379977897e-26)
(74.57397986566656, -4.86137607527994e-23)
(-46.55244480884272, -5.75158728239587e-18)
(18.84955592153876, -6.51241213607991e-9)
(80.51186705447822, -8.77942288424734e-15)
(63.63597817234566, -1.38045601340376e-19)
(12.566370614359172, -3.487342356209e-6)
(56.548667764616276, -2.76201244352236e-25)
(-21.991148575128552, -2.81426845748556e-10)
(6.283185307179586, -0.00186744273170799)
(-78.53981633974483, -7.77304449898755e-35)
(37.69911184307752, -4.24115118301608e-17)
(-96.21249475195584, -3.64447893646061e-17)
(21.991148575128552, -3553321280.84704)
(-97.3893722612836, -5.06212693294953e-43)
(100.53096491487338, -2.18754339521324e-44)
(-47.1238898038469, -3.42258854412123e-21)
(28.274333882308138, -1902773895292.16)
(94.2477796076938, -1.17141123423499e-41)
(-40.840704496667314, -1.83276760567157e-18)
(-34.55751918948773, -9.8143175935323e-16)
(-28.274333882308138, -5.25548517600645e-13)
(-85.41211308340019, -2.51221442358378e-31)
(-90.26031486697102, -4.81411641652805e-27)
(-34.984240419331734, -2.23213156812239e-14)
(-79.46066612582041, -2.90162212518714e-21)
(43.982297150257104, -7.92010695079813e-20)
(75.39822368615503, -1.79873633571987e-33)
(62.83185307179586, -5.15790006254285e-28)
(-84.3813701398482, -4.8309026479408e-34)
(-3.141592653589793, -0.0432139182637723)
(68.73962256845907, -1.1658553642877e-28)
(87.96459430051421, -6.27280941120808e-39)
(-9.42477796076938, -8.06995175703046e-5)
(31.41592653589793, -2.2711010683241e-14)
(31.25273809564381, -3.44251713837872e-14)
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=21.9911485751286x2=28.2743338823081Puntos máximos de la función:
x2=−15.707963267949x2=81.6814089933346x2=−72.2566310325652x2=50.2654824574367x2=25.1327412287183x2=−65.9734457253857x2=−53.4070751110265x2=−59.6902604182061x2=18.8495559215388x2=12.5663706143592x2=56.5486677646163x2=−21.9911485751286x2=6.28318530717959x2=−78.5398163397448x2=37.6991118430775x2=−97.3893722612836x2=100.530964914873x2=−47.1238898038469x2=94.2477796076938x2=−40.8407044966673x2=−34.5575191894877x2=−28.2743338823081x2=43.9822971502571x2=75.398223686155x2=62.8318530717959x2=−3.14159265358979x2=87.9645943005142x2=−9.42477796076938x2=31.4159265358979Decrece en los intervalos
[28.2743338823081,∞)Crece en los intervalos
(−∞,21.9911485751286]