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(−x2cos(2x)2sin(2x)−x32log(cos(2x)))cosx21(2x)=0Resolvermos esta ecuaciónRaíces de esta ecuación
x1=−59.6902604182061x2=87.9645943005142x3=−97.3893722612836x4=−56.5486677646163x5=40.8407044966673x6=31.4159265358979x7=−37.6991118430775x8=−81.6814089933346x9=−21.9911485751286x10=−15.707963267949x11=3.14159265358979x12=12.5663706143592x13=−87.9645943005142x14=−100.530964914873x15=−3.14159265358979x16=−78.5398163397448x17=−34.5575191894877x18=53.4070751110265x19=34.5575191894877x20=−94.2477796076938x21=6.28318530717959x22=−91.106186954104x23=−69.1150383789755x24=75.398223686155x25=97.3893722612836x26=65.9734457253857x27=15.707963267949x28=−50.2654824574367x29=−25.1327412287183x30=18.8495559215388x31=−12.5663706143592x32=37.6991118430775x33=−43.9822971502571x34=−53.4070751110265x35=−6.28318530717959x36=43.9822971502571x37=56.5486677646163x38=−65.9734457253857x39=−28.2743338823081x40=78.5398163397448x41=59.6902604182061x42=81.6814089933346x43=−47.1238898038469x44=100.530964914873x45=−9.42477796076938x46=−75.398223686155x47=−72.2566310325652x48=28.2743338823081x49=−31.4159265358979x50=21.9911485751286x51=62.8318530717959x52=9.42477796076938x53=50.2654824574367x54=94.2477796076938x55=72.2566310325652x56=84.8230016469244Signos de extremos en los puntos:
(-59.69026041820607, 1)
(87.96459430051421, 1)
(-97.3893722612836, 1)
(-56.548667764616276, 1)
(40.840704496667314, 1)
(31.41592653589793, 1)
(-37.69911184307752, 1)
(-81.68140899333463, 1)
(-21.991148575128552, 1)
(-15.707963267948966, 1)
(3.141592653589793, 1)
(12.566370614359172, 1)
(-87.96459430051421, 1)
(-100.53096491487338, 1)
(-3.141592653589793, 1)
(-78.53981633974483, 1)
(-34.55751918948773, 1)
(53.40707511102649, 1)
(34.55751918948773, 1)
(-94.2477796076938, 1)
(6.283185307179586, 1)
(-91.106186954104, 1)
(-69.11503837897546, 1)
(75.39822368615503, 1)
(97.3893722612836, 1)
(65.97344572538566, 1)
(15.707963267948966, 1)
(-50.26548245743669, 1)
(-25.132741228718345, 1)
(18.84955592153876, 1)
(-12.566370614359172, 1)
(37.69911184307752, 1)
(-43.982297150257104, 1)
(-53.40707511102649, 1)
(-6.283185307179586, 1)
(43.982297150257104, 1)
(56.548667764616276, 1)
(-65.97344572538566, 1)
(-28.274333882308138, 1)
(78.53981633974483, 1)
(59.69026041820607, 1)
(81.68140899333463, 1)
(-47.1238898038469, 1)
(100.53096491487338, 1)
(-9.42477796076938, 1)
(-75.39822368615503, 1)
(-72.25663103256524, 1)
(28.274333882308138, 1)
(-31.41592653589793, 1)
(21.991148575128552, 1)
(62.83185307179586, 1)
(9.42477796076938, 1)
(50.26548245743669, 1)
(94.2477796076938, 1)
(72.25663103256524, 1)
(84.82300164692441, 1)
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:
La función no tiene puntos mínimos
Puntos máximos de la función:
x56=−59.6902604182061x56=87.9645943005142x56=−97.3893722612836x56=−56.5486677646163x56=40.8407044966673x56=31.4159265358979x56=−37.6991118430775x56=−81.6814089933346x56=−21.9911485751286x56=−15.707963267949x56=3.14159265358979x56=12.5663706143592x56=−87.9645943005142x56=−100.530964914873x56=−3.14159265358979x56=−78.5398163397448x56=−34.5575191894877x56=53.4070751110265x56=34.5575191894877x56=−94.2477796076938x56=6.28318530717959x56=−91.106186954104x56=−69.1150383789755x56=75.398223686155x56=97.3893722612836x56=65.9734457253857x56=15.707963267949x56=−50.2654824574367x56=−25.1327412287183x56=18.8495559215388x56=−12.5663706143592x56=37.6991118430775x56=−43.9822971502571x56=−53.4070751110265x56=−6.28318530717959x56=43.9822971502571x56=56.5486677646163x56=−65.9734457253857x56=−28.2743338823081x56=78.5398163397448x56=59.6902604182061x56=81.6814089933346x56=−47.1238898038469x56=100.530964914873x56=−9.42477796076938x56=−75.398223686155x56=−72.2566310325652x56=28.2743338823081x56=−31.4159265358979x56=21.9911485751286x56=62.8318530717959x56=9.42477796076938x56=50.2654824574367x56=94.2477796076938x56=72.2566310325652x56=84.8230016469244Decrece en los intervalos
(−∞,−100.530964914873]Crece en los intervalos
[100.530964914873,∞)