ll-1 multiplying matrices
Ashley P.
Multiplying matrices isn't really that hard all you do is multiply the rows by the colomns and then add the rows together and you should have your answer. Let's have an example:
[3 5] * [[5]
[4]] now you simply multiply the 3times the 5 and you get 15 then you mult. the 5 times the 4 and you get 20 then you simply add the 15 and the 20 and the answer to your matrix is [35]! Really mult. matrices is really that simple just remember "RC Cola": you mult the rows times the columns.
11-4 The General Rotation Matrix
Now really I don't know all the particulars with this section, how ever I have my book so I will try to explain it as best I can. Now from what I understand there is a rotation matrix and here it is: [[cos theta -sin theta]
[sin theta -cos theta]] OK now you use this matrix when you have a shape you want ot move from one place to another. Say you have Rtheta (1,2) that equals the first column, and Rtheta (2,1) equals the second column. So basically you just pluging it in.