Sr Examen

Gráfico de la función y = x*tan(x)

v

Gráfico:

interior superior

Puntos de intersección:

mostrar?

Definida a trozos:

Solución

Ha introducido [src]
f(x) = x*tan(x)
f(x)=xtan(x)f{\left(x \right)} = x \tan{\left(x \right)}
f = x*tan(x)
Gráfico de la función
02468-8-6-4-2-1010-500500
Puntos de cruce con el eje de coordenadas X
El gráfico de la función cruce el eje X con f = 0
o sea hay que resolver la ecuación:
xtan(x)=0x \tan{\left(x \right)} = 0
Resolvermos esta ecuación
Puntos de cruce con el eje X:

Solución analítica
x1=0x_{1} = 0
x2=πx_{2} = \pi
Solución numérica
x1=59.6902604182061x_{1} = -59.6902604182061
x2=62.8318530717959x_{2} = -62.8318530717959
x3=97.3893722612836x_{3} = -97.3893722612836
x4=87.9645943005142x_{4} = 87.9645943005142
x5=56.5486677646163x_{5} = -56.5486677646163
x6=31.4159265358979x_{6} = 31.4159265358979
x7=69.1150383789755x_{7} = 69.1150383789755
x8=37.6991118430775x_{8} = -37.6991118430775
x9=81.6814089933346x_{9} = -81.6814089933346
x10=84.8230016469244x_{10} = -84.8230016469244
x11=21.9911485751286x_{11} = -21.9911485751286
x12=47.1238898038469x_{12} = 47.1238898038469
x13=15.707963267949x_{13} = -15.707963267949
x14=12.5663706143592x_{14} = -12.5663706143592
x15=12.5663706143592x_{15} = 12.5663706143592
x16=87.9645943005142x_{16} = -87.9645943005142
x17=53.4070751110265x_{17} = 53.4070751110265
x18=72.2566310325652x_{18} = 72.2566310325652
x19=100.530964914873x_{19} = -100.530964914873
x20=3.14159265358979x_{20} = -3.14159265358979
x21=34.5575191894877x_{21} = 34.5575191894877
x22=94.2477796076938x_{22} = -94.2477796076938
x23=6.28318530717959x_{23} = 6.28318530717959
x24=69.1150383789755x_{24} = -69.1150383789755
x25=97.3893722612836x_{25} = 97.3893722612836
x26=0x_{26} = 0
x27=65.9734457253857x_{27} = 65.9734457253857
x28=50.2654824574367x_{28} = -50.2654824574367
x29=15.707963267949x_{29} = 15.707963267949
x30=3.14159265358979x_{30} = 3.14159265358979
x31=25.1327412287183x_{31} = -25.1327412287183
x32=18.8495559215388x_{32} = -18.8495559215388
x33=40.8407044966673x_{33} = 40.8407044966673
x34=53.4070751110265x_{34} = -53.4070751110265
x35=37.6991118430775x_{35} = 37.6991118430775
x36=43.9822971502571x_{36} = -43.9822971502571
x37=18.8495559215388x_{37} = 18.8495559215388
x38=78.5398163397448x_{38} = -78.5398163397448
x39=6.28318530717959x_{39} = -6.28318530717959
x40=40.8407044966673x_{40} = -40.8407044966673
x41=43.9822971502571x_{41} = 43.9822971502571
x42=56.5486677646163x_{42} = 56.5486677646163
x43=65.9734457253857x_{43} = -65.9734457253857
x44=25.1327412287183x_{44} = 25.1327412287183
x45=78.5398163397448x_{45} = 78.5398163397448
x46=28.2743338823081x_{46} = -28.2743338823081
x47=75.398223686155x_{47} = 75.398223686155
x48=59.6902604182061x_{48} = 59.6902604182061
x49=34.5575191894877x_{49} = -34.5575191894877
x50=81.6814089933346x_{50} = 81.6814089933346
x51=47.1238898038469x_{51} = -47.1238898038469
x52=100.530964914873x_{52} = 100.530964914873
x53=9.42477796076938x_{53} = -9.42477796076938
x54=75.398223686155x_{54} = -75.398223686155
x55=72.2566310325652x_{55} = -72.2566310325652
x56=31.4159265358979x_{56} = -31.4159265358979
x57=28.2743338823081x_{57} = 28.2743338823081
x58=91.106186954104x_{58} = -91.106186954104
x59=21.9911485751286x_{59} = 21.9911485751286
x60=62.8318530717959x_{60} = 62.8318530717959
x61=9.42477796076938x_{61} = 9.42477796076938
x62=50.2654824574367x_{62} = 50.2654824574367
x63=94.2477796076938x_{63} = 94.2477796076938
x64=91.106186954104x_{64} = 91.106186954104
x65=84.8230016469244x_{65} = 84.8230016469244
Puntos de cruce con el eje de coordenadas Y
El gráfico cruce el eje Y cuando x es igual a 0:
sustituimos x = 0 en x*tan(x).
0tan(0)0 \tan{\left(0 \right)}
Resultado:
f(0)=0f{\left(0 \right)} = 0
Punto:
(0, 0)
Extremos de la función
Para hallar los extremos hay que resolver la ecuación
ddxf(x)=0\frac{d}{d x} f{\left(x \right)} = 0
(la derivada es igual a cero),
y las raíces de esta ecuación serán los extremos de esta función:
ddxf(x)=\frac{d}{d x} f{\left(x \right)} =
primera derivada
x(tan2(x)+1)+tan(x)=0x \left(\tan^{2}{\left(x \right)} + 1\right) + \tan{\left(x \right)} = 0
Resolvermos esta ecuación
Raíces de esta ecuación
x1=4.470438130231631013x_{1} = -4.47043813023163 \cdot 10^{-13}
x2=3.624535993419991017x_{2} = 3.62453599341999 \cdot 10^{-17}
x3=0x_{3} = 0
x4=3.466836968385381018x_{4} = 3.46683696838538 \cdot 10^{-18}
Signos de extremos en los puntos:
(-4.4704381302316267e-13, 1.99848170762288e-25)

(3.6245359934199923e-17, 1.31372611675971e-33)

(0, 0)

(3.4668369683853792e-18, 1.20189585653635e-35)


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=4.470438130231631013x_{1} = -4.47043813023163 \cdot 10^{-13}
x2=3.624535993419991017x_{2} = 3.62453599341999 \cdot 10^{-17}
x3=0x_{3} = 0
x4=3.466836968385381018x_{4} = 3.46683696838538 \cdot 10^{-18}
La función no tiene puntos máximos
Decrece en los intervalos
[3.624535993419991017,)\left[3.62453599341999 \cdot 10^{-17}, \infty\right)
Crece en los intervalos
(,4.470438130231631013]\left(-\infty, -4.47043813023163 \cdot 10^{-13}\right]
Puntos de flexiones
Hallemos los puntos de flexiones, para eso hay que resolver la ecuación
d2dx2f(x)=0\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0
(la segunda derivada es igual a cero),
las raíces de la ecuación obtenida serán los puntos de flexión para el gráfico de la función indicado:
d2dx2f(x)=\frac{d^{2}}{d x^{2}} f{\left(x \right)} =
segunda derivada
2(x(tan2(x)+1)tan(x)+tan2(x)+1)=02 \left(x \left(\tan^{2}{\left(x \right)} + 1\right) \tan{\left(x \right)} + \tan^{2}{\left(x \right)} + 1\right) = 0
Resolvermos esta ecuación
Raíces de esta ecuación
x1=97.3791034786112x_{1} = 97.3791034786112
x2=50.2455828375744x_{2} = 50.2455828375744
x3=59.6735041304405x_{3} = 59.6735041304405
x4=28.2389365752603x_{4} = 28.2389365752603
x5=91.0952098694071x_{5} = -91.0952098694071
x6=43.9595528888955x_{6} = -43.9595528888955
x7=47.1026627703624x_{7} = -47.1026627703624
x8=75.3849592185347x_{8} = -75.3849592185347
x9=78.5270825679419x_{9} = -78.5270825679419
x10=56.5309801938186x_{10} = -56.5309801938186
x11=94.2371684817036x_{11} = -94.2371684817036
x12=25.0929104121121x_{12} = -25.0929104121121
x13=37.672573565113x_{13} = 37.672573565113
x14=40.8162093266346x_{14} = 40.8162093266346
x15=53.3883466217256x_{15} = 53.3883466217256
x16=65.9582857893902x_{16} = 65.9582857893902
x17=40.8162093266346x_{17} = -40.8162093266346
x18=34.5285657554621x_{18} = -34.5285657554621
x19=69.100567727981x_{19} = 69.100567727981
x20=34.5285657554621x_{20} = 34.5285657554621
x21=81.6691650818489x_{21} = 81.6691650818489
x22=84.811211299318x_{22} = 84.811211299318
x23=81.6691650818489x_{23} = -81.6691650818489
x24=37.672573565113x_{24} = -37.672573565113
x25=18.7964043662102x_{25} = 18.7964043662102
x26=62.8159348889734x_{26} = -62.8159348889734
x27=25.0929104121121x_{27} = 25.0929104121121
x28=2.79838604578389x_{28} = 2.79838604578389
x29=87.9532251106725x_{29} = 87.9532251106725
x30=9.31786646179107x_{30} = -9.31786646179107
x31=12.4864543952238x_{31} = -12.4864543952238
x32=84.811211299318x_{32} = -84.811211299318
x33=50.2455828375744x_{33} = -50.2455828375744
x34=21.945612879981x_{34} = -21.945612879981
x35=100.521017074687x_{35} = -100.521017074687
x36=97.3791034786112x_{36} = -97.3791034786112
x37=6.12125046689807x_{37} = -6.12125046689807
x38=18.7964043662102x_{38} = -18.7964043662102
x39=43.9595528888955x_{39} = 43.9595528888955
x40=100.521017074687x_{40} = 100.521017074687
x41=31.3840740178899x_{41} = 31.3840740178899
x42=65.9582857893902x_{42} = -65.9582857893902
x43=72.2427897046973x_{43} = 72.2427897046973
x44=94.2371684817036x_{44} = 94.2371684817036
x45=78.5270825679419x_{45} = 78.5270825679419
x46=47.1026627703624x_{46} = 47.1026627703624
x47=87.9532251106725x_{47} = -87.9532251106725
x48=15.644128370333x_{48} = -15.644128370333
x49=75.3849592185347x_{49} = 75.3849592185347
x50=62.8159348889734x_{50} = 62.8159348889734
x51=28.2389365752603x_{51} = -28.2389365752603
x52=31.3840740178899x_{52} = -31.3840740178899
x53=15.644128370333x_{53} = 15.644128370333
x54=72.2427897046973x_{54} = -72.2427897046973
x55=56.5309801938186x_{55} = 56.5309801938186
x56=9.31786646179107x_{56} = 9.31786646179107
x57=53.3883466217256x_{57} = -53.3883466217256
x58=6.12125046689807x_{58} = 6.12125046689807
x59=69.100567727981x_{59} = -69.100567727981
x60=2.79838604578389x_{60} = -2.79838604578389
x61=59.6735041304405x_{61} = -59.6735041304405
x62=91.0952098694071x_{62} = 91.0952098694071
x63=21.945612879981x_{63} = 21.945612879981
x64=12.4864543952238x_{64} = 12.4864543952238

Intervalos de convexidad y concavidad:
Hallemos los intervales donde la función es convexa o cóncava, para eso veamos cómo se comporta la función en los puntos de flexiones:
Cóncava en los intervalos
[100.521017074687,)\left[100.521017074687, \infty\right)
Convexa en los intervalos
[2.79838604578389,2.79838604578389]\left[-2.79838604578389, 2.79838604578389\right]
Asíntotas horizontales
Hallemos las asíntotas horizontales mediante los límites de esta función con x->+oo y x->-oo
True

Tomamos como el límite
es decir,
ecuación de la asíntota horizontal a la izquierda:
y=limx(xtan(x))y = \lim_{x \to -\infty}\left(x \tan{\left(x \right)}\right)
True

Tomamos como el límite
es decir,
ecuación de la asíntota horizontal a la derecha:
y=limx(xtan(x))y = \lim_{x \to \infty}\left(x \tan{\left(x \right)}\right)
Asíntotas inclinadas
Se puede hallar la asíntota inclinada calculando el límite de la función x*tan(x), dividida por x con x->+oo y x ->-oo
limxtan(x)=,\lim_{x \to -\infty} \tan{\left(x \right)} = \left\langle -\infty, \infty\right\rangle
Tomamos como el límite
es decir,
ecuación de la asíntota inclinada a la izquierda:
y=,xy = \left\langle -\infty, \infty\right\rangle x
limxtan(x)=,\lim_{x \to \infty} \tan{\left(x \right)} = \left\langle -\infty, \infty\right\rangle
Tomamos como el límite
es decir,
ecuación de la asíntota inclinada a la derecha:
y=,xy = \left\langle -\infty, \infty\right\rangle x
Paridad e imparidad de la función
Comprobemos si la función es par o impar mediante las relaciones f = f(-x) и f = -f(-x).
Pues, comprobamos:
xtan(x)=xtan(x)x \tan{\left(x \right)} = x \tan{\left(x \right)}
- Sí
xtan(x)=xtan(x)x \tan{\left(x \right)} = - x \tan{\left(x \right)}
- No
es decir, función
es
par
Gráfico
Gráfico de la función y = x*tan(x)