a) Given the vectors: U= U2 = 1 U3 = -5 Explain why U1, U2, U3 form an orthogonal basis for 3 b)Let L be the line spanned u by Find the projection of u = (-3, 2, 22) onto the line L. c)Write the vector v = (1, 9, -1) as a linear combination of the basis vectors U1, U2, U3 d)Let W be the vector space spanned by uj and u2 Write y = (11, -8, 0) in the form y + z, where y is in W and z is orthogonal to W