Calculator Assumed 9. [10 marks: 4, 6] [TISC] 4 Given that y = du where x = f(u) and = -1 for all values of u. (1+x)3 (a) Use the chain rule to determine ~4 when y = du (b) If u = g (t), use the chain rule to determine dy when x = 0 and du = 2. dt dt