a b The voltage V in a circuit is given by V 3R 135R 1800R 200 where R is the resistance in ko 1 Compute dV dR Compute R values of turning point Compute whether R makes a maximum voltage or minimum voltage If y x show that logarithmic differentiation dy dx 2x 1 x 3 marks 3 marks 4 marks 1 by 6x In x 3 at the point x x 3 10 marks