[4 marks] This question continues from above. We know that the gradient operator a a V is defined as V =( ax' dy (a) Determine the dot product V . V b) Show that V . Vf = fax + fyy C) Make use of the finding from question 2(d), fill in the bracket, V . Vf = ( )g. d) Now, along this reasoning, we are going to write (V . V) f = ( )( )g, where ( ) is what you have found in part (c) above. With the help of your answers in question 1, show that 1 1 NO 4 2 2 ( V . V ) 2 f = - 29rr + -grrr + greer + 74 90000 + 74 900 73 900r + 7-2 900rr Hint: remember grer = grre = gerr