👉 Smoothness is a concept in mathematics and physics that describes the level of approximation or continuity of functions. A function is said to be "smooth" if it can be approximated by a continuous function, meaning that it is infinitely differentiable at every point in its domain. For example, consider the function f(x) = x^2 on the interval [-1, 1]. This function is smooth because it is continuously differentiable at every point in its domain. However, if we restrict our