Handwritten then box the final answers

2r: 2 _, Q10: Prove $7; : (g) r, where F : 1' [cos 90)? + Sin 9(ff] Hint: For a given a vector; xi : Am(t)i + Amy its derivative with respect to some variable t is d _, dAw(t)A (114?).(15) A : . (it (it Hr (it A J Remember also the chain rule