A =

  4  -1  -2
  1  2  -3
  0  0  4

AtA =

  17  -2  -11
  -2   5  -4
  -11  -4  29

eigv =

    2.9411
   12.3350
   35.7239

normA =  5.9769
For comparison: norm(A,2)=5.97695