当切点坐标已知时椭园、双曲线、抛物线y~2=2px的切线方程分别为:和yy_0=p(x+x_0)其中x_0,y_0为切点坐标。由此不难看出这样的规律,在这三种曲线的标准方程中,只要将x~2,y~2分别用xx_0,yy_0来代替,x用代替就能得到其切线方程,这是当二次曲线的方程是标准形式且切 When the coordinates of the tangent point are known, the tangent equations of ellipse, hyperbola, and parabola y~2=2px are: and yy_0=p(x+x_0) where x_0 and y_0 are the coordinates of the tangent point. It is not difficult to see such a rule, in the standard equations of these three curves, as long as the x~2, y~2 are replaced with xx_0, yy_0, respectively, x can be used instead of its tangent equation, which is when The equation of the subcurve is the standard form and cut