I solved 1-3, but I don't know how to do 4

1. Let u = (2,1,3) and v = (1,1,1). a. Find the projection of 11 onto v and call this vector w. b. Find the vector u w. c. Show that u w is orthogonal to v. d. Represent the vector u as the sum of two vectors, one which is parallel to v and one which is orthogonal to v