MathDB
IMC 1995 Problem 2

Source: IMC 1995

February 18, 2021
functioncalculusreal analysisIntegralinequalities

Problem Statement

Let ff be a continuous function on [0,1][0,1] such that for every x[0,1]x\in [0,1], we have x1f(t)dt1x22\int_{x}^{1}f(t)dt \geq\frac{1-x^{2}}{2}. Show that 01f(t)2dt13\int_{0}^{1}f(t)^{2}dt \geq \frac{1}{3}.