不等式问题与函数问题有着密切的联系,许多不等式问题可以通过构造函数,利用函数的性质获得解决. 例1 已知a、b∈R,且a+b+1=0,求证: (a-2)2+(b-3)2≥18. 分析若把不等式的左端看成关于a,b的二元函数,问题的实 The inequality problem is closely related to the function problem. Many inequality problems can be solved by constructing a function and using the properties of the function. Example 1 Known a, b∈R, and a+b+1=0, verification: (a-2 ) 2+(b-3)2≥18. If the left end of the inequality is viewed as a binary function on a,b, the problem is