(1 point) Suppose that the density of cars (in cars per mile) down a 20-mile stretch of the Pennsylvania Turnpike is approximated by 8(x)=275 (2+ sin(4x+0.125)), at a distance x miles from the Breezewood toll plaza. Sketch a graph of this function for 0x20. (a) Complete the Riemann sum that approximates the total number of cars on this 20-mile stretch (use Dx instead of Ax): Number= (b) Find the total number of cars on the 20-mile stretch. Number=