Consider the graph of y = f(t) shown below. Each of the shaded regions R1, R2 and R3 is bounded by the graph of y = f(t) and the t-axis. The area of region R1 is 4. . The area of region R2 is 5. . The area of region R3 is 6 R1 10 R2 Let A(a) = f(t) at. Use the graph and the provided areas to answer the following questions. a) A(5) b) A(8) c) A(10) d) Identify all intervals within [0, 10] on which A is increasing. Justify your answer.