Use the function f (x) to answer the questions: f (x) = 4x² - 7x - 15 Part A: What are the x-intercepts of the graph of f (x)? Show your work. (2 points) Part B: Is the vertex of the graph of f (x) going to be maximum or minimum? What are the coordinates of the vertex? Justify your answers and show your work. (3 points) Part C: What steps would you use to graph f (x)? Justify that you can use the answers obtained in Part A and B to draw the graph. (5 points)