8. [Geogebra Question] Build approximations to the definite integral Vidx using 1/2 several Riemann sums and compare with the exact result. (a) Define the given function vr. Graph of the function is shown automatically on the plot area. You can "swich off" the graph using circular button on the left from the input line. Similar switching buttons are present for all graphs and plots you create in Geogebra. (b) You will use the command RectangleSum ( (I, 1/2,2, n, 1/2) to calculate and visualize the Riemann sum in the case when the interval [1/2, 2] is divided into n subintervals. The last argument 1/2 in the brackets instructs the command to use middle points of subintervals in calculations of values of the function. The command RectangleSum(. .) produces both numerical value of the Riemann sum and a plot of the rectangles. You can "swich off" the plot using circular button on the left from the input line. (c) Use the command RectangleSum (