(a) For the function, z= xy Oz express OZ in its simplest form. xty ov Ox (3 (b) If z = In(e* +e" ), show that Oz - =1 Ox (3 (c) For the implicit function: z=x2 + 2xy+ 2y +1=0 (i) determine dy in its simplest form. dx (ii) show that day is given by: dy 1 dx2 dx2 (x+ 2y) (d) A heat transfer process is defined by the equation: wr3 p = a 4 Using the method of small differences, determine the percentage change in p if w increases by 2%, r decreases by 3%, and a increases by 1%