$$\lim_{x \to \infty}\left(\frac{\tan{\left(\frac{x}{2} \right)}}{\tan{\left(3 x \right)}}\right)$$
$$\lim_{x \to 0^-}\left(\frac{\tan{\left(\frac{x}{2} \right)}}{\tan{\left(3 x \right)}}\right) = \frac{1}{6}$$
More at x→0 from the left$$\lim_{x \to 0^+}\left(\frac{\tan{\left(\frac{x}{2} \right)}}{\tan{\left(3 x \right)}}\right) = \frac{1}{6}$$
More at x→0 from the right$$\lim_{x \to 1^-}\left(\frac{\tan{\left(\frac{x}{2} \right)}}{\tan{\left(3 x \right)}}\right) = \frac{\tan{\left(\frac{1}{2} \right)}}{\tan{\left(3 \right)}}$$
More at x→1 from the left$$\lim_{x \to 1^+}\left(\frac{\tan{\left(\frac{x}{2} \right)}}{\tan{\left(3 x \right)}}\right) = \frac{\tan{\left(\frac{1}{2} \right)}}{\tan{\left(3 \right)}}$$
More at x→1 from the right$$\lim_{x \to -\infty}\left(\frac{\tan{\left(\frac{x}{2} \right)}}{\tan{\left(3 x \right)}}\right)$$
More at x→-oo