Question 1 - 20 marks This question is based on your work on MU123 up to and incinding Unit 10. (a) This part of the question concerns the quadratic equation 0) (ii) (iii) 32:2 17$ 12 = 0. Find the discriminant of the quadratic expression 3:1:2 173: 12. What does this discriminant tell you about the number of solutions of the equation? Explain your answer briey. What does this discriminant tell you about the graph of y = 32:2 172: 12? (b) Figure 1 shows part of the graph of the quadratic function y: :s2+7:s+18. Figure 1 Explain why the graph of the quadratic function y = :c2 | 72: | 18 is nshaped. Write down the yintercept. Find the equation of the axis of symmetry of the parabola given by y = 2:2 + 72: + 18, explaining your method. Use your answer to part (b)(iii) to nd the coordinates of the vertex of the parabola given by y = 2:2 + 7.1: + 18. [2] [2] [1] [1] [1] [2]