用柯西不等式巧解竞赛题２１５６００江苏张家港市一中任夏明设ａ１，ａ２，…，ａｎ及ｂ１，ｂ２，…，ｂｎ为任意实数，则当且仅当时等号成立．此即柯西不等式．对某些竞赛题，若能注意因式的巧妙分拆，结构的灵活变形，并应用柯西不等式，常能收到出奇制胜的效果．例１... Using Cauchy inequalities to solve competition problems 215600 in Zhangjiagang City, Jiangsu Province, a summer any set a1, a2, ..., an and b1, b2, ..., bn any real number, then when and only when the equal sign is established. This is Cauchy inequality. For some contest questions, if we can pay attention to the clever deconstruction of the factors, the flexible deformation of the structure, and the application of Cauchy inequality, we can often receive the effect of surprise. Example 1...