Homework 1 Clarifications


The compositing equation is a color vector equation.  But, you should be thinking in terms of a separate equation per color channel.
 
Where it asks "is it generally possible to estimate all the unknowns", you can read that as simply "is it possible to solve for all the unknowns."  (This same remark holds for problem 1b.)
The reference to Euler angle rotations is just a definition.  I.e., rotations about the canonical axes are Euler angle rotations.
Reflections generally replace objects with their mirror images (as well as re-orient them).
 
Your answer to this problem must use cross and/or dot products.  You must use geometric reasoning to explain why your use of these operations will distinguish a reflection from a rotation.