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