有关一元二次方程实根的分布问题的习题,散见于某些教材和许多习题集中。对这些习题一般都是根据题设要求,直接用判别式、韦达定理和求根公式等知识通过解不等式(组)求解的。这种方法往往相当麻烦。例如,问k为什么实数时方程,x~2+2(k+3)x+2k+ The exercises about the distribution of the real roots of the quadratic equations are scattered in some textbooks and many exercises. These problems are generally solved by solving inequalities (groups) using knowledge of discriminants, Weeda’s theorem, and root-finding formulae. This method is often quite troublesome. For example, ask why k is the real time equation, x~2+2(k+3)x+2k+