[Edu-sig] Teacher looking for software for displaying 3D vectors and planes

[Daniel Ajoy]

http://www.reddit.com/r/math/comments/8riul/teacher_looking_for_software_for_displaying_3d/

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Hi, I have spent a good few hours on a fruitless search for something that will help my students understand 3D vectors better. What I'm teaching is basically stuff like this: The equation of a line in three dimensions (something like r = a + t b (b is a direction vector, t is a parameter)

The equation of a plane as r . n = a . n

Intersection between lines and planes, angles between two planes, between a plane and a line, identifying lines as skew, parallel, etc., techniques like cross product for finding plane normals.

(This is all part of the UK "A-level" Maths if you're wondering).

I'm looking for something to help visualise this type of mathematics, because almost all students say this area is one of the hardest of the course, and they never seem to be very good at constructing an appropriate image in their mind that would allow them to see a sensible strategy for finding the solution. I feel sure that my combination of metre rules and desks and pieces of paper is insufficient for them to build a good mental picture.

So I want something that will not only show planes and lines on the projector screen in a good quality 3D representation, but will (v important) allow me to rotate the image or the objects in the image, or move lines and see how a point on the line moves with it, etc.

Software doesn't have to be free, but I doubt my school would be prepared to pay several hundred dollars. I teach English qualifications in China, by the way, so bear that in mind.

Edit: I forgot to mention we don't have internet in the classroom at the moment, so it needs to be an offline tool.

Thanks if anyone has a suggestion.
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