(a) Use the triangle inequality: ||u + v|| <= ||u|| + ||v|| to prove that

Question

(i) ||u - v|| <= ||u|| + ||v||
(ii) ||u|| - ||v|| <= ||u - v||
(b) If ||u|| = 5 and ||v|| = 3, what are the smallest and largest possible values of ||u - v|| and ||v - u||?