2. (a) Assume that h(z, y) = Vyz2 - y3 - 2. (i) Calculate and ay (ii) Determine the linearisation of h at the point (-3, 2). (iii) Use this linearisation to approximate the value h( -2.8, 1.9). [10 marks] (b) Use the method of Lagrange multipliers to find the critical points of the function -x In(x) - 2y In(y) - 42 In(z) on the surface given by exp(2r) exp(4y) exp(8z - 7) = 1. Show all steps of the process and explain your reasoning. [15 marks]