Problem 16 (Orthogonal Complement). Let w = (1, -2, -1, 3) be a vector in R4. Find, 1. An orthogonal basis for W+. 2. An orthonormal basis for W+. Problem 17 (Orthogonal Complement). Consider M2×2 with the inner product (A, B) an orthogonal basis for the orthogonal complement of, 1. diagonal matrices. 2. symmetric matrices. = trace (BTA). Find Problem 18 (Orthogonal Complement). Let U, W be subspaces of a finite-dimensional inner product space V. Show that, 1. (U+W) U+0W+. 2. (UnW)=U++W+.