Find the sum of the given vectors. a = 1, 3, ?3 , b = 0, 0, 6 <1,3,?3> Illustrate geometrically. a starts at (x, y, z) = (0, 0, 0) and ends at (x, y, z) = . b starts at (x, y, z) = and ends at (x, y, z) = . a + b starts at (x, y, z) = and ends at (x, y, z) = .