Talk:Cylinder

Cylindric section equation source?

The equation for the semi-major axis a in the section Properties/Cylindric sections appears to be wrong. With the current definition, it would imply that the semi-major axis becomes infinite if the cylinder is aligned with the normal of the secant plane. If the equation is changed to a=r / cos(alpha), then the semi-major axis becomes the radius of the cylinder when the cylinder is normal to the plane. What is the source of this equation and is the equation for eccentricity also incorrect?Grumbins (talk) 04:53, 30 June 2022 (UTC)

definition?

Definition, does the parallell lines need to to be line segments of equal length?

Which parallel lines? Are you referring to §Cylindric sections? In that case, the line segments would be be the height h of the cylinder. Andy Dingley (talk) 10:27, 8 March 2017 (UTC)

Adding a helpful online program to the link list?

Hello everyone, since this is my first edit to the Wikipedia I would like to know if I can add a helpful link to the main page of this article under "External Links". The link is for an online program: Cylinder Calculation 3D - there you specify two values only and all the other values get calculated automatically, plus you have an interactive 3D visualization of the resulting 3d cylinder, and some nice graphics. Thank you in advance Matheretter (talk) 11:15, 31 August 2015 (UTC)

I think online calculators make bad external links. In any case, can you explain why you think it passes WP:ELNO? —David Eppstein (talk) 15:45, 31 August 2015 (UTC)

Hi David and thanks for your reply. I have checked all the points from your link and do not see why the provided link should not be suitable. https://en.wikipedia.org/wiki/Wikipedia:External_links#What_can_normally_be_linked says that "Sites that contain neutral and accurate material that is relevant to an encyclopedic understanding of the subject". I would say the linked program helps understanding cylinders essentially better since you can interact in 3d with them, plus when you set the values of the cylinder it changes its shape accordingly and calculates all others, so a big help for students and teachers. But this is my POV. That's why I asked here on this talk page. Matheretter (talk) 16:34, 31 August 2015 (UTC)

definition error

The introduction is wrong. Cylinders are not limited to objects having a surface that is "a fixed distance from the axis" [of the cylinder] - this applies only to a circular cylinder. Can the last author please fix this and any other inconsistencies.

Thanks,

2001:569:737B:AD00:D421:2F70:F52F:CCBE (talk) 18:39, 24 November 2015 (UTC)

Typo? cylinder with arbitrary axis

i think this line: $B=-x\cos(\theta )\sin(\phi )+y\sin(\theta )\cos(\phi )+z\cos(\phi )$

should actually be: $B=-x\cos(\theta )\sin(\phi )+y\sin(\theta )\sin(\phi )+z\cos(\phi )$

Avi --185.46.212.75 (talk) 11:16, 15 June 2016 (UTC)

Requested Move discussion in progress.

There is a discussion going on at the Talk Page for "Cylinder" to move that page to Cylinder (disambiguation). It is implicit in the proposal that this page would move to Cylinder, but that is not formally part of the proposal. You may want to participate in that discussion. --MrStoofer (talk) 11:10, 9 December 2016 (UTC)

As the move has been done, the (closed) discussion is now at Talk:Cylinder (disambiguation). D.Lazard (talk) 10:04, 8 November 2017 (UTC)

Move discussion in progress

There is a move discussion in progress on Talk:Cylinder which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 21:46, 9 December 2016 (UTC)

As the move has been done, the (closed) discussion is now at Talk:Cylinder (disambiguation). D.Lazard (talk) 10:05, 8 November 2017 (UTC)

"Rod (geometry)" listed at Redirects for discussion

A discussion is taking place to address the redirect Rod (geometry). The discussion will occur at Wikipedia:Redirects for discussion/Log/2021 March 8#Rod (geometry) until a consensus is reached, and readers of this page are welcome to contribute to the discussion. CiaPan (talk) 20:36, 8 March 2021 (UTC)

"Rod (shaft)" listed at Redirects for discussion

A discussion is taking place to address the redirect Rod (shaft). The discussion will occur at Wikipedia:Redirects for discussion/Log/2021 March 9#Rod (shaft) until a consensus is reached, and readers of this page are welcome to contribute to the discussion. Adumbrativus (talk) 06:09, 9 March 2021 (UTC)

The page Cylinder is incorrect.

According to James Tanton a cylinder is a made from creating a base shape on a plane, making a congruent shape on a parallel plane and connecting each edge/point to the corresponding edge/point on the other base. This is not the definition that is on the Cylinder page.

The source for this is: [1]https://www.youtube.com/watch?v=XS4xSytnAm8

James Tanton also mentions this in his Geometry course, sold at: https://www.thegreatcourses.com/courses/geometry-an-interactive-journey-to-mastery. Pigly3 (talk) 01:44, 6 December 2023 (UTC)

There are several related concepts of 'cylinder' used in mathematics, and which one is more convenient depends on context. –jacobolus (t) 03:38, 6 December 2023 (UTC)

Tanton's definition is equivalent to that of the article's first paragraph. —Tamfang (talk) 07:14, 14 December 2023 (UTC)