I need help with themath problem below:

The average number of vehicles waiting in line to enter a parking ramp can be modeled by the function

f(x) = x^2/2*(1-x)

where x is a quantity between 0 and 1 known as the traffic intensity. Find the rate of change of the number of vehicles in line with respect to the traffic intensity for x = 0.3.

Please include all your steps so I can understand what you did.