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Límite de la función log(x-pi/2)/tan(5*x)

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Ha introducido [src]
      /   /    pi\\
      |log|x - --||
      |   \    2 /|
 lim  |-----------|
   pi \  tan(5*x) /
x->--+             
   2               
limxπ2+(log(xπ2)tan(5x))\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right)
Limit(log(x - pi/2)/tan(5*x), x, pi/2)
Método de l'Hopital
Tenemos la indeterminación de tipo
0/0,

tal que el límite para el numerador es
limxπ2+1tan(5x)=0\lim_{x \to \frac{\pi}{2}^+} \frac{1}{\tan{\left(5 x \right)}} = 0
y el límite para el denominador es
limxπ2+1log(2xπ2)=0\lim_{x \to \frac{\pi}{2}^+} \frac{1}{\log{\left(\frac{2 x - \pi}{2} \right)}} = 0
Vamos a probar las derivadas del numerador y denominador hasta eliminar la indeterminación.
limxπ2+(log(xπ2)tan(5x))\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right)
=
Introducimos una pequeña modificación de la función bajo el signo del límite
limxπ2+(log(2xπ2)tan(5x))\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\log{\left(\frac{2 x - \pi}{2} \right)}}{\tan{\left(5 x \right)}}\right)
=
limxπ2+(ddx1tan(5x)ddx1log(2xπ2))\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\frac{d}{d x} \frac{1}{\tan{\left(5 x \right)}}}{\frac{d}{d x} \frac{1}{\log{\left(\frac{2 x - \pi}{2} \right)}}}\right)
=
limxπ2+((2xπ)(5tan2(5x)5)log(xπ2)22tan2(5x))\lim_{x \to \frac{\pi}{2}^+}\left(- \frac{\left(2 x - \pi\right) \left(- 5 \tan^{2}{\left(5 x \right)} - 5\right) \log{\left(x - \frac{\pi}{2} \right)}^{2}}{2 \tan^{2}{\left(5 x \right)}}\right)
=
limxπ2+(ddx((2xπ)log(xπ2)22tan2(5x))ddx15tan2(5x)5)\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\frac{d}{d x} \left(- \frac{\left(2 x - \pi\right) \log{\left(x - \frac{\pi}{2} \right)}^{2}}{2 \tan^{2}{\left(5 x \right)}}\right)}{\frac{d}{d x} \frac{1}{- 5 \tan^{2}{\left(5 x \right)} - 5}}\right)
=
limxπ2+(10xlog(xπ2)2tan(5x)+10xlog(xπ2)2tan3(5x)2xlog(xπ2)xtan2(5x)πtan2(5x)25πlog(xπ2)2tan(5x)log(xπ2)2tan2(5x)5πlog(xπ2)2tan3(5x)+πlog(xπ2)xtan2(5x)πtan2(5x)250tan3(5x)25tan4(5x)+50tan2(5x)+25+50tan(5x)25tan4(5x)+50tan2(5x)+25)\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\frac{10 x \log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan{\left(5 x \right)}} + \frac{10 x \log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan^{3}{\left(5 x \right)}} - \frac{2 x \log{\left(x - \frac{\pi}{2} \right)}}{x \tan^{2}{\left(5 x \right)} - \frac{\pi \tan^{2}{\left(5 x \right)}}{2}} - \frac{5 \pi \log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan{\left(5 x \right)}} - \frac{\log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan^{2}{\left(5 x \right)}} - \frac{5 \pi \log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan^{3}{\left(5 x \right)}} + \frac{\pi \log{\left(x - \frac{\pi}{2} \right)}}{x \tan^{2}{\left(5 x \right)} - \frac{\pi \tan^{2}{\left(5 x \right)}}{2}}}{\frac{50 \tan^{3}{\left(5 x \right)}}{25 \tan^{4}{\left(5 x \right)} + 50 \tan^{2}{\left(5 x \right)} + 25} + \frac{50 \tan{\left(5 x \right)}}{25 \tan^{4}{\left(5 x \right)} + 50 \tan^{2}{\left(5 x \right)} + 25}}\right)
=
limxπ2+(10xlog(xπ2)2tan(5x)+10xlog(xπ2)2tan3(5x)2xlog(xπ2)xtan2(5x)πtan2(5x)25πlog(xπ2)2tan(5x)log(xπ2)2tan2(5x)5πlog(xπ2)2tan3(5x)+πlog(xπ2)xtan2(5x)πtan2(5x)250tan3(5x)25tan4(5x)+50tan2(5x)+25+50tan(5x)25tan4(5x)+50tan2(5x)+25)\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\frac{10 x \log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan{\left(5 x \right)}} + \frac{10 x \log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan^{3}{\left(5 x \right)}} - \frac{2 x \log{\left(x - \frac{\pi}{2} \right)}}{x \tan^{2}{\left(5 x \right)} - \frac{\pi \tan^{2}{\left(5 x \right)}}{2}} - \frac{5 \pi \log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan{\left(5 x \right)}} - \frac{\log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan^{2}{\left(5 x \right)}} - \frac{5 \pi \log{\left(x - \frac{\pi}{2} \right)}^{2}}{\tan^{3}{\left(5 x \right)}} + \frac{\pi \log{\left(x - \frac{\pi}{2} \right)}}{x \tan^{2}{\left(5 x \right)} - \frac{\pi \tan^{2}{\left(5 x \right)}}{2}}}{\frac{50 \tan^{3}{\left(5 x \right)}}{25 \tan^{4}{\left(5 x \right)} + 50 \tan^{2}{\left(5 x \right)} + 25} + \frac{50 \tan{\left(5 x \right)}}{25 \tan^{4}{\left(5 x \right)} + 50 \tan^{2}{\left(5 x \right)} + 25}}\right)
=
00
Como puedes ver, hemos aplicado el método de l'Hopital (utilizando la derivada del numerador y denominador) 2 vez (veces)
Gráfica
-3.0-2.5-2.0-1.5-1.0-0.50.00.51.01.52.02.53.0-10000000000000001000000000000000
A la izquierda y a la derecha [src]
      /   /    pi\\
      |log|x - --||
      |   \    2 /|
 lim  |-----------|
   pi \  tan(5*x) /
x->--+             
   2               
limxπ2+(log(xπ2)tan(5x))\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right)
0
00
= 0.00966883345446983
      /   /    pi\\
      |log|x - --||
      |   \    2 /|
 lim  |-----------|
   pi \  tan(5*x) /
x->---             
   2               
limxπ2(log(xπ2)tan(5x))\lim_{x \to \frac{\pi}{2}^-}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right)
0
00
= (-0.00974778342223482 + 0.00401661837640065j)
= (-0.00974778342223482 + 0.00401661837640065j)
Respuesta rápida [src]
0
00
Otros límites con x→0, -oo, +oo, 1
limxπ2(log(xπ2)tan(5x))=0\lim_{x \to \frac{\pi}{2}^-}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right) = 0
Más detalles con x→pi/2 a la izquierda
limxπ2+(log(xπ2)tan(5x))=0\lim_{x \to \frac{\pi}{2}^+}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right) = 0
limx(log(xπ2)tan(5x))\lim_{x \to \infty}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right)
Más detalles con x→oo
limx0(log(xπ2)tan(5x))=sign(log(2)+log(π)+iπ)\lim_{x \to 0^-}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right) = - \infty \operatorname{sign}{\left(- \log{\left(2 \right)} + \log{\left(\pi \right)} + i \pi \right)}
Más detalles con x→0 a la izquierda
limx0+(log(xπ2)tan(5x))=sign(log(2)+log(π)+iπ)\lim_{x \to 0^+}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right) = \infty \operatorname{sign}{\left(- \log{\left(2 \right)} + \log{\left(\pi \right)} + i \pi \right)}
Más detalles con x→0 a la derecha
limx1(log(xπ2)tan(5x))=log(1+π2)+iπtan(5)\lim_{x \to 1^-}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right) = \frac{\log{\left(-1 + \frac{\pi}{2} \right)} + i \pi}{\tan{\left(5 \right)}}
Más detalles con x→1 a la izquierda
limx1+(log(xπ2)tan(5x))=log(1+π2)+iπtan(5)\lim_{x \to 1^+}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right) = \frac{\log{\left(-1 + \frac{\pi}{2} \right)} + i \pi}{\tan{\left(5 \right)}}
Más detalles con x→1 a la derecha
limx(log(xπ2)tan(5x))\lim_{x \to -\infty}\left(\frac{\log{\left(x - \frac{\pi}{2} \right)}}{\tan{\left(5 x \right)}}\right)
Más detalles con x→-oo
Respuesta numérica [src]
0.00966883345446983
0.00966883345446983