4.4.13. Find a basis for the orthogonal complement of the following subspaces of R³: (a) the plane 3x+4y 5z = 0; (b) the line in the direction (-2,1,3); (c) the image of the - matrix 1 2 - 1 3 -2 0 2 1 ; (d) the cokernel of the same matrix. - -1 2 1 4