MathDB
Continuous Function on Open Interval

Source: Romanian District Olympiad 2018 - Grade XI - Problem 4

March 10, 2018
functioncontinuityreal analysis

Problem Statement

Let a<ba < b be real numbers and let f:(a,b)Rf : (a, b) \to \mathbb{R} be a function such that the functions g:(a,b)Rg : (a, b) \to \mathbb{R}, g(x)=(xa)f(x)g(x) = (x - a) f(x) and h:(a,b)Rh : (a, b) \to \mathbb{R}, h(x)=(xb)f(x)h(x) = (x - b) f(x) are increasing. Show that the function ff is continuous on (a,b)(a, b).