How do u do this? i'm honestly so blank

Iwill make brain if you me correctly fill this out needs due today pls and send it back to me (click the link and you will get it)

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.

3382-299=3383- ? fill in the blank?