Question regarding variable name

Dr.Peterson

Elite Member
Joined
Nov 12, 2017
Messages
10,590
Hi, in the below matrix, can someone please tell me what the 'c' represents? and what is the sub symbol next to it?
thanks in adavnced
View attachment 25221
source: https://en.wikipedia.org/wiki/Rotation_matrix
When you see an unfamiliar symbol, always look just before or after its first appearance for the definition!

Here is your snip, with one more line of context:

1613827019758.png

Now, can you tell me what \(c_\theta\) means?

They are just abbreviating, to reduce the size of this monster. I often write just c and s for the same purpose in the middle of a long calculation.
 

markraz

Full Member
Joined
Feb 19, 2014
Messages
332
When you see an unfamiliar symbol, always look just before or after its first appearance for the definition!

Here is your snip, with one more line of context:

View attachment 25224

Now, can you tell me what \(c_\theta\) means?

They are just abbreviating, to reduce the size of this monster. I often write just c and s for the same purpose in the middle of a long calculation.
Theta?
 

Dr.Peterson

Elite Member
Joined
Nov 12, 2017
Messages
10,590
Yes, \(c_\theta\), with subscript theta, is the cosine of the angle theta by which something is rotated. And \(s_\theta = \sin(\theta)\).
 

markraz

Full Member
Joined
Feb 19, 2014
Messages
332
Yes, \(c_\theta\), with subscript theta, is the cosine of the angle theta by which something is rotated. And \(s_\theta = \sin(\theta)\).
ooooh dunce cap lol... I'm slow.....Thanks for your help appreciate it
 
Last edited:

Subhotosh Khan

Super Moderator
Staff member
Joined
Jun 18, 2007
Messages
23,779
ooooh dunce cap lol... I'm slow.....Thanks for your help appreciate it
Here we send people to the "corner" - and sit there for a while facing the walls.

If you need direction to the corner - ask Jomo.
 
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