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Límite de la función cot(2*x)^2*tanh(3*x)^2

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Ha introducido [src]
     /   2          2     \
 lim \cot (2*x)*tanh (3*x)/
x->0+                      
$$\lim_{x \to 0^+}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right)$$
Limit(cot(2*x)^2*tanh(3*x)^2, x, 0)
Método de l'Hopital
Tenemos la indeterminación de tipo
0/0,

tal que el límite para el numerador es
$$\lim_{x \to 0^+} \tanh^{2}{\left(3 x \right)} = 0$$
y el límite para el denominador es
$$\lim_{x \to 0^+} \frac{1}{\cot^{2}{\left(2 x \right)}} = 0$$
Vamos a probar las derivadas del numerador y denominador hasta eliminar la indeterminación.
$$\lim_{x \to 0^+}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \tanh^{2}{\left(3 x \right)}}{\frac{d}{d x} \frac{1}{\cot^{2}{\left(2 x \right)}}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\left(6 - 6 \tanh^{2}{\left(3 x \right)}\right) \cot^{3}{\left(2 x \right)} \tanh{\left(3 x \right)}}{4 \cot^{2}{\left(2 x \right)} + 4}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{6 \cot^{3}{\left(2 x \right)} \tanh{\left(3 x \right)}}{4 \cot^{2}{\left(2 x \right)} + 4}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \frac{1}{4 \cot^{2}{\left(2 x \right)} + 4}}{\frac{d}{d x} \frac{1}{6 \cot^{3}{\left(2 x \right)} \tanh{\left(3 x \right)}}}\right)$$
=
$$\lim_{x \to 0^+}\left(- \frac{4 \left(- 4 \cot^{2}{\left(2 x \right)} - 4\right) \cot{\left(2 x \right)}}{\left(\frac{6 \cot^{2}{\left(2 x \right)} + 6}{6 \cot^{4}{\left(2 x \right)} \tanh{\left(3 x \right)}} + \frac{3 \tanh^{2}{\left(3 x \right)} - 3}{6 \cot^{3}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}}\right) \left(4 \cot^{2}{\left(2 x \right)} + 4\right)^{2}}\right)$$
=
$$\lim_{x \to 0^+}\left(- \frac{4 \left(- 4 \cot^{2}{\left(2 x \right)} - 4\right) \cot{\left(2 x \right)}}{\left(\frac{6 \cot^{2}{\left(2 x \right)} + 6}{6 \cot^{4}{\left(2 x \right)} \tanh{\left(3 x \right)}} + \frac{3 \tanh^{2}{\left(3 x \right)} - 3}{6 \cot^{3}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}}\right) \left(4 \cot^{2}{\left(2 x \right)} + 4\right)^{2}}\right)$$
=
$$\frac{9}{4}$$
Como puedes ver, hemos aplicado el método de l'Hopital (utilizando la derivada del numerador y denominador) 2 vez (veces)
Gráfica
A la izquierda y a la derecha [src]
     /   2          2     \
 lim \cot (2*x)*tanh (3*x)/
x->0+                      
$$\lim_{x \to 0^+}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right)$$
9/4
$$\frac{9}{4}$$
= 2.25
     /   2          2     \
 lim \cot (2*x)*tanh (3*x)/
x->0-                      
$$\lim_{x \to 0^-}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right)$$
9/4
$$\frac{9}{4}$$
= 2.25
= 2.25
Respuesta rápida [src]
9/4
$$\frac{9}{4}$$
Otros límites con x→0, -oo, +oo, 1
$$\lim_{x \to 0^-}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right) = \frac{9}{4}$$
Más detalles con x→0 a la izquierda
$$\lim_{x \to 0^+}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right) = \frac{9}{4}$$
$$\lim_{x \to \infty}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right)$$
Más detalles con x→oo
$$\lim_{x \to 1^-}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right) = \frac{- 2 e^{6} + 1 + e^{12}}{\tan^{2}{\left(2 \right)} + 2 e^{6} \tan^{2}{\left(2 \right)} + e^{12} \tan^{2}{\left(2 \right)}}$$
Más detalles con x→1 a la izquierda
$$\lim_{x \to 1^+}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right) = \frac{- 2 e^{6} + 1 + e^{12}}{\tan^{2}{\left(2 \right)} + 2 e^{6} \tan^{2}{\left(2 \right)} + e^{12} \tan^{2}{\left(2 \right)}}$$
Más detalles con x→1 a la derecha
$$\lim_{x \to -\infty}\left(\cot^{2}{\left(2 x \right)} \tanh^{2}{\left(3 x \right)}\right)$$
Más detalles con x→-oo
Respuesta numérica [src]
2.25
2.25