3. Consider the function f(x = 2x2+3x+6 x+2 A. Find f"(x . (Show your work!) B. Graph f"(x on your calculator and use this graph to answer the following questions: On what interval(s) is f(x concave up, and how did you use the graph of f"(x to estimate this? On what interval(s) is f(x concave down, and how did you use the graph of f" (x to estimate this? Note: You don't need to include a sketch of y = f"(x in your answer. 4. Consider the function f(x - x4+7x+3 As in the last problem, find f"(x (showing all work), and use the graph of this function to estimate where f(x is concave up and where f(x is concave down. You don't need to include a sketch of the graph of f"(x in your