Rotation about an arbitrary axis- X-Axis and Y-axis rotation

Discussion in 'Homework Help' started by zulfi100, Mar 27, 2015.

1. zulfi100 Thread Starter Active Member

Jun 7, 2012
395
1
Hi,
I got a example related to 3d rotation about an abitrary axis. initially I have following diagram:

However after rotation about x-axis, the diagram changes to:

I cant understand how to draw the full cube? Why is there no downward perpendicular from A? Please guide me.

Zulfi.

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Jun 17, 2014
3,753
791
Hi,

What cube?

3. zulfi100 Thread Starter Active Member

Jun 7, 2012
395
1
Hi,
Thanks for your reply. The first figure shows the cube but the second figure is not a cube. This is the thing which i want to understand. Please guide me.

Zulfi.

4. MrAl Distinguished Member

Jun 17, 2014
3,753
791
Hello again,

Ok, if i understand you right, you are drawing a cube, then rotating it, then you want to draw it again.

This isnt as hard as it may sound at first. There are 8 points that define the 8 corners of the cube. Rotate all 8, then connect the dots
If you have trouble with determining what dots to connect, then draw more dots...start by rotating mid points between each corner and that will give you three dots per edge. If you want more, calculate more and perhaps plot them all, then view what you've plotted.
A mid point can be found by using the mid point formula, then use two more times between that new point and the corners to get two more points, and if you do this enough times the cube will almost draw itself if you plot all the points.