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