1. A point light source having an intensity of 1 watt per steradian (emitting uniformly in all directions) is 1 meter away from the center of a square patch of surface, of edge length 1 meter. Find the irradiance at the center of the square, and at the corner.
   
   
   
   
2. Following are two different versions of the rendering equation. For each one, provide a picture and short phrase or equation describing each term (e.g., L(x' -> x'') is the radiance traveling from point x' to point x''). Then, show that the equations are the same by deriving one of them from the other.
    
   

Please save your answers in a pdf file and submit via email to funk@princeton.edu (please include "COS 526" in the subject line).