【摘要】 空间两条直线有共面和异面两种位置关系,对于两条直线位置关系的判定,通常的方法是判定两条直线所通过已知点构成的矢量与两条直线的方向矢量的混合积是否等于零。若混合积等于零,则两直线共面,若混合积不等于零,则两条直线异面。但对于直线的一般方程而言,此判定方法比较繁琐,不易解决实际问题。利用两条直线共面定理可以判定直纹曲面上直母线间的位置关系,更好地帮助研究直纹曲面的性质。更多还原

【Abstract】 Two straight lines have coplanar and different planes in space,the usual method of determine the relationship between the location of the two straight lines is whether two straight lines by vector consisting of known points in the direction of the vector of mixed product is equal to zero.If mixed product equal to zero,the two lines coplanar,if mixed product is not equal to zero,the two lines in different planes.But for general equation of straight line,this determination method is tedious,not easy to solve practical problems.The coplanar theorem of two straight lines can be used to determine on a ruled surface of the positional relationship between the straight generatrix,to better help the study of properties of the ruled surface.更多还原