URL:https://math.libretexts.org/@api/deki/files/8979/imageedit_40_7572917707.png?revision=1&size=bestfit&width=522&height=522
掲載元:https://math.libretexts.org/Courses/University_of_California_Davis/UCD_Mat_21C:_Multivariate_Calculus/11:_Vectors_and_the_Geometry_of_Space/11.6:_Cylinders_and_Quadric_Surfaces