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