探究在什么条件下,才能使某个对象为定值.解析几何中的这类探究型定值问题,由于条件与定值均需探究,对考生分析问题和解决问题的能力提出了更高的要求.此类问题往往归结为一个多元函数问题,求解必须突破三个难点:一是在该表达式涉及的多个变量中,抓住问题的主要矛盾,正确辨认主 Explore the conditions under which an object can be set as a fixed value. This type of inquiry-type fixed value problem in analytic geometry, because conditions and fixed values ​​need to be explored, the examinee’s ability to analyze problems and solve problems is higher. Requirements. Such problems often boil down to a multivariate function problem. The solution must break through three difficulties: First, in the multiple variables involved in the expression, seize the main contradiction of the problem and correctly identify the main