摘要
讨论二次曲线切线的相关问题,证明无奇异点的二次曲线若有沿渐近方向的切线,则一定是包含两条平行直线的线心二次曲线;过二次曲线外的中心,曲线没有切线.
This paper provides two conclusions about tangent of quadratic curves：（1） The quadratic curve without singular point is a conic of central line consisting of two parallel lines,if it has a tangent following asymptotic direction;（2） There is no tangent through the outside center of conic.
出处
《高等数学研究》
2012年第2期5-7,共3页
Studies in College Mathematics
关键词
二次曲线
切线
奇异点
渐近方向
quadratic curve
tangent
singular point
asymptotic direction
