Respuesta :

[tex] \lim_{x \to 0} \frac{x}{sin 3x} = \\ =\frac{0}{0}= \\ = \lim_{x \to 0} \frac{3x}{3sin3x} = [/tex]
= 1/3  ( because the limit as x approaches 0 of  t/sin t = 1 ).