一道积分不等式的四种证法

Four Proofs of an Integral Inequality

针对某高等数学教材中的一道关于积分不等式的证明题,分别利用柯西-施瓦茨不等式、拉格朗日微分中值定理、积分性质或二重积分性质给出四种证明方法.

Based on the Cauchy-Schwartz inequality, Lagrange, differential mean value theorem, integral properties and double integral properties, this paper gathers four proofs to an int eggral inequality.