Summarize the pertinent information obtained by applying the graphing strategy and sketch the graph of y=f(x).​f(x)=(x−6)x2−12x−72 Question content area bottom Part 1 Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice. A. The domain of f is enter your response here. ​(Type your answer in interval notation. Type an exact​answer, using radicals as needed. Use a comma to separate answers as​ needed.) B. The domain of f is empty.