Orthogonal projection onto a line (3)

Let L be the line L parameterized by L(t)=(2t,3t,t) for tR, and let T:R3R3 be the linear transformation that is orthogonal projection onto L.

  1. Describe ker(T) and im(T), either implicitly (using equations in x,y,z) or parametrically.
  2. List the eigenvalues of T and their geometric multiplicities.
  3. Find a basis for each eigenspace of T.
  4. Let A be the matrix for T with respect to the standard basis. Find a diagonal matrix B and an invertible matrix S such that B=S1AS. (You do not have to compute A.)