0 Accuracy and validity of any calculations or algebraic manipulations 0 Clear justication or explanation of techniques and rules used 0 Clear communication of mathematical ideas through diagrams 0 Use of correct mathematical notation and terminology 0 You must Show step by step working out. . The total surface area of a cylinderical water tank is 6007f square units. If its radius is r and height is h. (a) Show that, h : 3% 7r. (3 marks) (b) Hence, show that the volume of the cylinder is given by: V(r) : 3007M" 777's (1 mark) (c) Determine the value of r for which the volume of the tank will be a maximum. (3 mark) (d) Hence, nd the maximum volume of the cylinderical tank. (1 mark) i Find the equation of the tangent to the curve f(:t) : 2sin(x g) + 1 at x : g (4 marks)