笔者在研读贵刊2010号问题时,发现其作图方法虽然巧妙,但前提是要知道抛物线的对称轴和焦点.本文改进其方法,在仅知道其对称轴的情况下,得到过抛物线上任意一点作切线的方法,并予以证明.其原理是:先求出过抛物线上任意一点的切线与对称轴的交点,然后再作出这个交点.连接这两点,就作出了过抛物线上任意一点的切线.沿着这条思路,也找到了过椭圆和双曲线上任意 When I read your issue No. 2010, I found that though its drawing method is ingenious, the premise is to know the symmetry axis and the focus of the parabola.This paper improves its method and obtains a parabolic curve with only knowing its symmetry axis The method of tangential point is proved by the principle that the intersection point of the tangent line and the symmetry axis at any point on the parabola is obtained first and then the intersection point is made and the connection is made at any point on the parabola Tangents. Along this line of thought, also found oval and hyperbolic arbitrary