1) (80 points) Derive the expression of the optimal packet size Smax that maximizes the efficiency. Express Smax as a function of the bit rate br, the propagation time Tp, and the bit error rate ber. (Hint: a function f(x) is optimal for some value x0 if and only if f'(x0)=df(x)dx=0. In other words, derive the function f(x) and solve f'(x0) = 0.

1)consider the following code snippet: #ifndef book_h#define book_hconst double max_cost = 1000.0; class book{public: book(); book(double new_cost); void set_cost(double new_cost); double get_cost() const; private: double cost; }; double calculate_terms(book bk); #endifwhich of the following is correct? a)the header file is correct as given.b)the definition of max_cost should be removed since header files should not contain constants.c)the definition of book should be removed since header files should not contain class definitions.d)the body of the calculate_terms function should be added to the header file.

Write a car class having two private member variables called tank and speed. write public methods called pumpgas and gofast. the method pumpgas gets an integer for gas that must be pumped. that value needs to be added to tank (no more than 20 gallons). it must return the amount of gas that is purchased ($4 per gallon). the method gofast should increase the speed by 5 each time it is called.write a constructor for the above class that initialized both variables to zero.write a tostring to display both the tank and speed when the car is printed.modify the car class to implement the interface comparable and an interface called carinter having the public methods in carinter.write the main program to create an array of size 5 of type car. create 5 car objects having each location of the array to refer to one of the cars. test the pumpgas, gofast, equals method on the array items. write an enhanced loop to print all the car values (using a tostring written last time).write a generic method to find the minimum of four items. pass int, double, char, string and car objects to test this method.

Most shops require the technician to enter a starting and ending time on the repair order to track the actual time the vehicle was in the shop and closed out by the office. this time is referred to as _ time ? a. comeback b. ro c. cycle d. lead