Kelly's story is truly inspirational. Kelly has shown that pure determination, dedication and hard work can and does change a person's life. At Life Leisure we have loved being part of Kelly's journey.
In calculus (a branch of mathematics), a differentiable function of one real variable is a function whose derivative exists at each point in its domain.
Two facts about these functions are: 1  if is a monotonic function defined on an interval, then is differentiable almost everywhere on, i.e. the set of numbers in such that is not differentiable in has Lebesgue measure zero. 2  In addition, this result cannot be improved to countable: see Cantor function.