(c) This part of the question concerns the quadratic function y: 1:2 +18$+ 42. {1) Write the quadratic expression 3:2 + 18:: + 42 in completed-square forrn. (ii) Use the completed-square form from part (c)(i) to solve the equation 3:2 + 18:: + 42 = U, leaving your answer in exact (surd) forrn. (iii) Use the completed-square form from part (e}(i) to write down the coordinates of the vertex of the parabola y = 3:2 + 183: + 42. iv Provide a sketch of the raph of the parabola = 3:2 + 18:1: + 42, { l s it either by hand or by using a suitable graphing software package like Graphplotter