@article{Öztürk_İlarslan_Koç Öztürk_Nesovic_2018, title={A note on Lamarle formula in Minkowski $3$-space}, volume={49}, url={https://journals.math.tku.edu.tw/index.php/TKJM/article/view/2653}, DOI={10.5556/j.tkjm.49.2018.2653}, abstractNote={The Lamarle formula is known as a simple relation between the Gaussian curvature and the distribution parameter of a non-developable ruled surface. In this paper, we obtain the Lamarle formula of a non-developable ruled surface with pseudo null base curve and null director vector field in Minkowski $3$-space. We also obtain the corresponding striction line and distribution parameter of such surface. We prove that there is no Lamarle formula when the director vector field is spacelike and its derivative is null, because the ruled surface in that case is a lightlike plane. Finally, we give some examples.}, number={4}, journal={Tamkang Journal of Mathematics}, author={Öztürk, Ufuk and İlarslan, Kazım and Koç Öztürk, Esra Betül and Nesovic, Emilija}, year={2018}, month={Dec.}, pages={291–300} }