【摘要】 本文证明了球面曲线，可展曲面上正交于直母线的曲线的测地挠率为零。并改进陈永丰文［２］关于“全挠率”的一个定理的证法。更多还原

【Abstract】 In this paper we prove that "The geodesics torsion of the curve on thesphere which is orthogonal with the reetitinera generator on a developable surface iszero", then we improve the proof of theorem in [2].更多还原