(4) (5pts each) Let r(t) = (tet, t In(t), sin(3t)) (a) Find lim r(t) t-+2 (b) Find r' (t). (5) (6pts each) Let u = (t, t2 +3, 3+3 + 7t). Use vector derivative properties to find: [u'(t) . u(t) ] (b) # lu(t ) x u'(t ) ]