Sir i am stuck for this question

1 2 4. Let A = 2 5 . l 4 (a) (3 points) Compute ATA. (b) (4 points) What does the (l, 2)-entry of ATA represent (the entry in row 1, column 2)? Relate this quantity to the columns of A. (c) (14 points) Let W = 001.4, which is a plane in R3. Find the vector w E W that is l as close as possible to the vector v = 3 . 3 (d) (4 points) Compute the distance from v to the plane W