为了二次函数都知道:二次函数y=ax2+bx+c(a、b、c为常数,a≠0),当y=0时,则此函数形式化为ax2+bx+c=0(a≠0).即二次函数就化为一元二次方程了。所以一元二次方程实际上就是二次函数的特殊形式。因此,二次函数与x轴的交点问题就可以用一元二次方程根的分布和判定定理来解决。下面我们就用例子来谈谈二次函数与x轴的交点。 For the quadratic function, we know that quadratic function y = ax2 + bx + c (a, b, c are constants, a ≠ 0). When y = 0, then this function is formalized as ax2 + bx + c = 0 (a ≠ 0), that is, the quadratic function becomes a quadratic equation. So the quadratic equation is actually a special form of quadratic function. Therefore, the intersection of the quadratic function and the x axis can be solved by the distribution and decision theorem of the root of the quadratic equation. Here we use examples to talk about the intersection of the quadratic function and the x axis.