在不等式的证明中,常遇到一些问题,看似简单,但却很难找到突破口,这时我们不妨从不等式的结构出发,在已学习过的知识基础上进行联想,构造一个与不等式相关的函数模型,将问题转化,从而使不等式得到证明.一、构造一次函数例1设a、b、c∈R,且它们的绝对值不大于1,求证ab+bc+ca+1≥ In the proof of inequality, we often encounter some problems, seemingly simple, but it is difficult to find a breakthrough. At this time, we may wish to proceed from the structure of inequality and make associations based on the learned knowledge to construct an inequality-related Function model, the problem is transformed, so that the inequality is proved. First, the construction of a function example 1 set a, b, c ∈ R, and their absolute value is not greater than 1, to verify ab + bc + ca + 1 ≥