Knowledge [2 marks each] 1. Differentiate each of the following: aly = - cos2 x b) y = sin(20) - 2 cos(20) c) f(0) = - - sin(20 - It) d) f(x) = sin(sin x) e) f(x) = cos(cos x) n) f(8) = cos(70) - cos(50) gly = 3x sin x h) f(t) = 2t2 cos(2t)