二次函数y＝ax‘十伽十c（一0）中，a确定抛物线的开口方向，c确定抛物线与y轴的交点位置，b确定什么呢？这就是本文要讨论的问题．当抛物线的对称轴在、轴的。侧时人u一乒＜0，即乒＞0．由此可知b与。同号；当抛物线的对称轴在，轴的右侧时，则一半＞0，即去＜0．由此可知b与a In the quadratic function y=ax ‘Ten Gamma c’ (zero), a determines the direction of the opening of the parabola, and c determines the position of the intersection of the parabola and the y-axis. What does b determine? This is the issue that this article will discuss. When the axis of symmetry of the parabola, the axis. When the side of a human ping <0, that is, ping> 0. It can be seen that b and. Same number; when the axis of symmetry of the parabola is on the right side of the axis, then half >0, that is, go to <0. It can be seen that b and a