要判断直线与二次曲线的位置关系，通常将直线方程代入二次曲线方程，整理成一元二次方程，由该一元二次方程的判别式来判断．这样作运算量大，计算烦杂，易出错，更难用于解决其它与此有关问题．是否能用二次曲线方程和直线方程的常数直接作出直线与二次曲线位置关系的判... To determine the positional relationship between a straight line and a quadratic curve, the linear equation is usually substituted into the quadratic curve equation, and it is organized into a quadratic equation, which is judged by the discriminant of the quadratic equation. This makes the calculation volume large, the calculation complicated, error-prone, and more difficult to solve other related issues. Whether can use the constant of quadratic curve equation and linear equation to directly make the position relation between the straight line and the quadratic curve...