Hi Guys, I need help. I try out part(a) and (b).But it seem to me...my answer is not correct or too brief. Can anyone assist me? As for part (c). I'm not sure what A means here. Is it referring to A = [ cost -sint sint cost]? And what abt part (d), what does B means here? Can someone assist me how to do part (c) and (d)? Please advise. Thanks.