韦达定理用在圆锥曲线中,可灵活解决直线与圆锥曲线的相交问题,关键是巧设直线方程,消去一个元得另一个元的一元二次方程,本文专门介绍韦达定理在抛物线中的应用,兹举例说明.例1已知抛物线y2=4x,过点P(4,0)的直线与抛物线相交于A(x1,y1)、B(x2,y2)两点,试求y12+y22的最小值.解设过点P(4,0)的直线方程为x=ky+4,代入抛物线方程并整理,得 Vedic theorem is used in the conic curve, which can flexibly solve the intersection of the straight line and the conic curve. The key point is to formulate a straight line equation and eliminate a unary quadratic equation of another element. This paper introduces the Vedic theorem in the parabola Example 1 It is known that a straight line with a parabola y2 = 4x and an excessive point P (4,0) intersects a parabola at two points A (x1, y1) and B (x2, y2) The solution of the point P (4,0) of the linear equation is x = ky +4, into the parabolic equation and finishing, too