Consider the image in Figure 3.6, a gray-scale rendering of a painting by Mondrian (1872-1944). We build a 256 x 256 matrix A of pixels based on this image by ignoring grey zones, assigning +1 to horizontal or vertical black lines, +2 at the intersections, and zero elsewhere. The horizontal lines occur at row indices 100, 200 and 230, and the vertical ones, at columns indices 50, 230.

1. What is nullspace of the matrix?
2. What is its rank?

2(2) 0 (1) y = Az