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