You can model an arch at your school using the equation y = -0.5(x + 4)(x - 4), where x and y are measured in feet. The x-axis represents the ground. Find the width of the arch at ground level.
The width of the arch at ground level is
feet

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.