Ten elementary functions y = f(x), each on a window fitted to its shape, from the cusp of √|x| at the origin to x/(1 + x²). sin x / x tends to 1 at x = 0 and its integral over the whole line is π. x/(1 + x²) peaks at x = 1 with height ½. e⁻⁰·³ˣ sin 2x loses 61 % of its