1. [4 marks|] Approximate 3 / 4z dx 0 Draw a picture of the graph of the function showing your rectangles. using three equal subintervals. Indicate the width and height of each rectangle. Show clearly how you got your estimate. (Use left endpoints like in the textbook). 2. [4 marks] What does 2 / 2z dz 1 Draw a picture of the graph of the function showing the areas and indicate how they are signed (do they count as positive or negative?). represent in terms of area? Using the formula for area of a triangle (half the base times height), calculate this definite integral. \f4. [4 marks] Rain falls at a rate of 12 3t> mm per hour from = 2 to = 2 (measured in hours). Express the total rainfall over this period of time using a definite integral. How much rain falls over this period? State your answer in an English sentence. 5. |4 marks| Calculate the indefinite integral Simplify your answer, if you can. 6. [4 marks] Substitute u = x2 + 1 into 2 2ac V x2 + 1 dac o and write down the new definite integral using only u, carefully showing your reasoning. Now calculate the definite integral