二次函数y=ax2+bx+c的图象与其系数a、b、c之间的关系可归纳总结如下.1.a决定抛物线的开口方向:当a0时,抛物线开口向上;当a0时,抛物线开口向下.2.a决定抛物线的开口大小:a越大,抛物线开口越小;a越小,抛物线开口越大.3.a、b的符号决定抛物线的对称轴:a、b同号,抛物线的对称轴 The relationship between the image of the quadratic function y=ax2+bx+c and its coefficients a, b, c can be summarized as follows. 1.a determines the opening direction of the parabola: when a0, the parabola opens upward; when a0, The parabolic opening is downward. 2.a determines the size of the opening of the parabola: the larger the a, the smaller the opening of the parabola; the smaller the a, the larger the opening of the parabola. 3. The signs of a and b determine the axis of symmetry of the parabola: a, b , the axis of symmetry of the parabola