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 three different versions of the rendering equation. For each one, provide a picture ad short phrase or equation describing each term (e.g., I(x' -> x'') is the intensity of light traveling from point x' to point x''). Then, show that the equations are the same by deriving two of them from one of the others.

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