在实际解题时,有一类问题的条件总是“‘/(、动一。“+衍+c,当二呀仁一1,1]时,有了(川任[一1,1日”,我称其为“仁一1,川”问题.这类问题没有程序性的解法,但只要能灵活运用一次、二次函数的相关性质,并结合其它知识(主要是不等式),注意所求结论的结构,即可得出结沦. 例1设f(二) In the practical problem solving, the condition of one type of problem is always “’/(, move one. ”+ yan + c, when Erye Renyi 1, 1], there is (chuan ren [1, 1 day]“ I call it the ”Renyi 1, Chuan" problem. There is no procedural solution to this kind of problem, but as long as we can flexibly use the related properties of primary and secondary functions and combine other knowledge (mainly inequalities), we must pay attention to The conclusion of the structure, you can conclude the knot. Example 1 set f (2)