Tenemos la indeterminación de tipo
0/0,
tal que el límite para el numerador es
$$\lim_{x \to 0^+} \operatorname{asin}^{3}{\left(5 x \right)} = 0$$
y el límite para el denominador es
$$\lim_{x \to 0^+}\left(- \sin{\left(x \right)} + \tan{\left(x \right)}\right) = 0$$
Vamos a probar las derivadas del numerador y denominador hasta eliminar la indeterminación.
$$\lim_{x \to 0^+}\left(\frac{\operatorname{asin}^{3}{\left(5 x \right)}}{- \sin{\left(x \right)} + \tan{\left(x \right)}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \operatorname{asin}^{3}{\left(5 x \right)}}{\frac{d}{d x} \left(- \sin{\left(x \right)} + \tan{\left(x \right)}\right)}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{15 \operatorname{asin}^{2}{\left(5 x \right)}}{\sqrt{1 - 25 x^{2}} \left(- \cos{\left(x \right)} + \tan^{2}{\left(x \right)} + 1\right)}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{15 \operatorname{asin}^{2}{\left(5 x \right)}}{- \cos{\left(x \right)} + \tan^{2}{\left(x \right)} + 1}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} 15 \operatorname{asin}^{2}{\left(5 x \right)}}{\frac{d}{d x} \left(- \cos{\left(x \right)} + \tan^{2}{\left(x \right)} + 1\right)}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{150 \operatorname{asin}{\left(5 x \right)}}{\sqrt{1 - 25 x^{2}} \left(\left(2 \tan^{2}{\left(x \right)} + 2\right) \tan{\left(x \right)} + \sin{\left(x \right)}\right)}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{150 \operatorname{asin}{\left(5 x \right)}}{\left(2 \tan^{2}{\left(x \right)} + 2\right) \tan{\left(x \right)} + \sin{\left(x \right)}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} 150 \operatorname{asin}{\left(5 x \right)}}{\frac{d}{d x} \left(\left(2 \tan^{2}{\left(x \right)} + 2\right) \tan{\left(x \right)} + \sin{\left(x \right)}\right)}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{750}{\sqrt{1 - 25 x^{2}} \left(\left(\tan^{2}{\left(x \right)} + 1\right) \left(2 \tan^{2}{\left(x \right)} + 2\right) + 2 \left(2 \tan^{2}{\left(x \right)} + 2\right) \tan^{2}{\left(x \right)} + \cos{\left(x \right)}\right)}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{750}{\cos{\left(x \right)} + 6 \tan^{4}{\left(x \right)} + 8 \tan^{2}{\left(x \right)} + 2}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{750}{\cos{\left(x \right)} + 6 \tan^{4}{\left(x \right)} + 8 \tan^{2}{\left(x \right)} + 2}\right)$$
=
$$250$$
Como puedes ver, hemos aplicado el método de l'Hopital (utilizando la derivada del numerador y denominador) 3 vez (veces)