在解析几何中解决有关直线与圆锥曲线的交点及弦长问题时,我们常常避免直接求解交点坐标,而是巧妙地利用根与系数的关系作为桥梁,通过整体代换达到目标式的求解.这就是我们常说的“设而不求法”.类似地,在利用导数探究函数性质的过程中,我们常常遇到某些难以确定的极值点或某些难以计算的代数式,这时我们并不正面求出点的坐标,而是利用该点满足的条件式进行代换消元以解决这一棘手问题.这就是我今天要阐述的函 When solving the problem of intersection and chord length between straight line and conic in analytic geometry, we often avoid direct solution to the intersection point coordinates. Instead, we use the relationship between roots and coefficients as a bridge to achieve the objective solution through the whole substitution. We often say “instead of seeking ” Similarly, in the use of derivatives to explore the nature of the function, we often encounter some difficult to determine the extreme points or some difficult to calculate the algebraic, then we Instead of finding the coordinates of a point positively, we use the conditional formula that the point satisfies to solve the thorny problem, which is what I am going to elaborate today