Test 2 5 4. Let S be the twodimensional subspace of R4 spanned by 1 0 x1 = 10 and xQ = (1) 0 1 (a) Find an orthonormal basis for S J- by hand and ShOW all of your steps. (b) Give a geometric description of S and S J'. (c) Determine the projection matrix P that projects vectors in R4 onto SJ: Show all of your work