韦达定理“如果方程ax~2+bx+c=0(a■0)的两根是x_1,x_2，那么，，x_1+x_2=-(b/a),x_1·x_2=(c/a)”.它提示了一元二次方程根与系数的内在联系,无论在代数、几何、三角,还是在解析几何中都有着其广泛的应用。然而,许多学生虽然理解了韦达定理的内容,但不能正确加以运用。究其原因,笔者以为,主要是由于教师的教法不 The Weida Theorem: If the two roots of the equation ax~2+bx+c=0 (a■0) are x_1,x_2, then, x_1+x_2=-(b/a), x_1·x_2=(c/a )". It hints at the intrinsic link between the root and the coefficient of the quadratic equation, and it has its wide applications in algebra, geometry, triangles, and analytical geometry. However, although many students understand the content of Vedic theorem, they cannot be used correctly. The reason why the author thinks that this is mainly because the teacher’s teaching method is not