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