在解决解析几何问题时,我们经常会遇到这样一种情况:已知条件与所求结论之间难以建立联系,总感到缺少一些有关量.这时我们不妨改变一下思维方式或解题思路,根据题目中具体的条件大胆设置一些变量,作为联系题设条件和结论或已知量与未知量的桥梁.这 When solving analytical geometry problems, we often encounter such a situation: it is difficult to establish a connection between the known conditions and the conclusions we are seeking, and we always feel that we lack some relevant quantities. At this time, we may wish to change our way of thinking or solve problems. According to the specific conditions in the topic, boldly set some variables as a bridge to link the conditions and conclusions or the known and unknown quantities.