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Límite de la función x^2*(-sin(2*x)+2*sin(x)-x*(-cos(2*x)+cos(x)))/((1-cos(x))^2*sin(x)^2)

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Ha introducido [src]
     / 2                                                \
     |x *(-sin(2*x) + 2*sin(x) - x*(-cos(2*x) + cos(x)))|
 lim |--------------------------------------------------|
x->0+|                          2    2                  |
     \              (1 - cos(x)) *sin (x)               /
$$\lim_{x \to 0^+}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right)$$
Limit((x^2*(-sin(2*x) + 2*sin(x) - x*(-cos(2*x) + cos(x))))/(((1 - cos(x))^2*sin(x)^2)), x, 0)
Método de l'Hopital
Tenemos la indeterminación de tipo
0/0,

tal que el límite para el numerador es
$$\lim_{x \to 0^+}\left(- x \cos{\left(x \right)} + x \cos{\left(2 x \right)} + 2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right) = 0$$
y el límite para el denominador es
$$\lim_{x \to 0^+}\left(\frac{\sin^{2}{\left(x \right)} \cos^{2}{\left(x \right)}}{x^{2}} - \frac{2 \sin^{2}{\left(x \right)} \cos{\left(x \right)}}{x^{2}} + \frac{\sin^{2}{\left(x \right)}}{x^{2}}\right) = 0$$
Vamos a probar las derivadas del numerador y denominador hasta eliminar la indeterminación.
$$\lim_{x \to 0^+}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right)$$
=
Introducimos una pequeña modificación de la función bajo el signo del límite
$$\lim_{x \to 0^+}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + 2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \left(- x \cos{\left(x \right)} + x \cos{\left(2 x \right)} + 2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)}{\frac{d}{d x} \left(\frac{\sin^{2}{\left(x \right)} \cos^{2}{\left(x \right)}}{x^{2}} - \frac{2 \sin^{2}{\left(x \right)} \cos{\left(x \right)}}{x^{2}} + \frac{\sin^{2}{\left(x \right)}}{x^{2}}\right)}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{x \sin{\left(x \right)} - 2 x \sin{\left(2 x \right)} + \cos{\left(x \right)} - \cos{\left(2 x \right)}}{- \frac{2 \sin^{3}{\left(x \right)} \cos{\left(x \right)}}{x^{2}} + \frac{2 \sin^{3}{\left(x \right)}}{x^{2}} + \frac{2 \sin{\left(x \right)} \cos^{3}{\left(x \right)}}{x^{2}} - \frac{4 \sin{\left(x \right)} \cos^{2}{\left(x \right)}}{x^{2}} + \frac{2 \sin{\left(x \right)} \cos{\left(x \right)}}{x^{2}} - \frac{2 \sin^{2}{\left(x \right)} \cos^{2}{\left(x \right)}}{x^{3}} + \frac{4 \sin^{2}{\left(x \right)} \cos{\left(x \right)}}{x^{3}} - \frac{2 \sin^{2}{\left(x \right)}}{x^{3}}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{x \sin{\left(x \right)} - 2 x \sin{\left(2 x \right)} + \cos{\left(x \right)} - \cos{\left(2 x \right)}}{- \frac{2 \sin^{3}{\left(x \right)} \cos{\left(x \right)}}{x^{2}} + \frac{2 \sin^{3}{\left(x \right)}}{x^{2}} + \frac{2 \sin{\left(x \right)} \cos^{3}{\left(x \right)}}{x^{2}} - \frac{4 \sin{\left(x \right)} \cos^{2}{\left(x \right)}}{x^{2}} + \frac{2 \sin{\left(x \right)} \cos{\left(x \right)}}{x^{2}} - \frac{2 \sin^{2}{\left(x \right)} \cos^{2}{\left(x \right)}}{x^{3}} + \frac{4 \sin^{2}{\left(x \right)} \cos{\left(x \right)}}{x^{3}} - \frac{2 \sin^{2}{\left(x \right)}}{x^{3}}}\right)$$
=
$$-\infty$$
Como puedes ver, hemos aplicado el método de l'Hopital (utilizando la derivada del numerador y denominador) 1 vez (veces)
Gráfica
A la izquierda y a la derecha [src]
     / 2                                                \
     |x *(-sin(2*x) + 2*sin(x) - x*(-cos(2*x) + cos(x)))|
 lim |--------------------------------------------------|
x->0+|                          2    2                  |
     \              (1 - cos(x)) *sin (x)               /
$$\lim_{x \to 0^+}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right)$$
-oo
$$-\infty$$
= -301.99668867637
     / 2                                                \
     |x *(-sin(2*x) + 2*sin(x) - x*(-cos(2*x) + cos(x)))|
 lim |--------------------------------------------------|
x->0-|                          2    2                  |
     \              (1 - cos(x)) *sin (x)               /
$$\lim_{x \to 0^-}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right)$$
oo
$$\infty$$
= 301.99668867637
= 301.99668867637
Otros límites con x→0, -oo, +oo, 1
$$\lim_{x \to 0^-}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right) = -\infty$$
Más detalles con x→0 a la izquierda
$$\lim_{x \to 0^+}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right) = -\infty$$
$$\lim_{x \to \infty}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right)$$
Más detalles con x→oo
$$\lim_{x \to 1^-}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right) = - \frac{- 2 \sin{\left(1 \right)} - \cos{\left(2 \right)} + \cos{\left(1 \right)} + \sin{\left(2 \right)}}{- 2 \sin^{2}{\left(1 \right)} \cos{\left(1 \right)} + \sin^{2}{\left(1 \right)} \cos^{2}{\left(1 \right)} + \sin^{2}{\left(1 \right)}}$$
Más detalles con x→1 a la izquierda
$$\lim_{x \to 1^+}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right) = - \frac{- 2 \sin{\left(1 \right)} - \cos{\left(2 \right)} + \cos{\left(1 \right)} + \sin{\left(2 \right)}}{- 2 \sin^{2}{\left(1 \right)} \cos{\left(1 \right)} + \sin^{2}{\left(1 \right)} \cos^{2}{\left(1 \right)} + \sin^{2}{\left(1 \right)}}$$
Más detalles con x→1 a la derecha
$$\lim_{x \to -\infty}\left(\frac{x^{2} \left(- x \left(\cos{\left(x \right)} - \cos{\left(2 x \right)}\right) + \left(2 \sin{\left(x \right)} - \sin{\left(2 x \right)}\right)\right)}{\left(1 - \cos{\left(x \right)}\right)^{2} \sin^{2}{\left(x \right)}}\right)$$
Más detalles con x→-oo
Respuesta rápida [src]
-oo
$$-\infty$$
Respuesta numérica [src]
-301.99668867637
-301.99668867637