Chapter 7 Code Examples

MATLAB Code Examples

format bank
bill=input('Enter the amount of the bill (in dollars): ');
if (bill <= 10)
     tip = 1.8;
elseif (bill > 10) & (bill <= 60)
     tip = bill*0.18;
else
     tip = bill*0.2;
end
disp('The tip is (in dollars):')
disp(tip)

n = 1;
while (n ~= 0)
     x = input (‘Resistance: ‘);
     switch x
          case 100
          disp (x)
          case 200
          disp (x)
          case 300
          disp (x)
          case 400
          disp (x)
          otherwise
          n = 0;
     end
end

Python Code Examples

bill=int(input('Enter the amount of the bill (in dollars): '))
if (bill <= 10):
     tip=1.8
elif (bill>10)and(bill<=60):
     tip=bill*0.18
else:
     tip=bill*0.2
print('The tip is (in dollars): %0.2f'% (tip))

Exercises

1. Expanding on problem 1 from chapter 6, implement your algorithm. The problem description is restated below.
   Write a script called “quadroots” to solve the real roots of a quadratic equation:

      

   
   Your algorithm should ask the user for the coefficients. To calculate the roots of the equation, your algorithm should calculate the discriminant D given by:

      

   
   If D > 0, the algorithm displays a message: “The equation has two roots” and then displays the roots.
   If D = 0, the algorithm displays a message: “The equation has one root”, and then displays the root.
   If D < 0, the algorithm displays a message: “The equation has no real roots”.
2. Expanding on problem 2 from chapter 6, implement your algorithm. The problem description is restated below.
   Write a program that calculates the cost of a car rental according to the following price schedule:

Type of Car	Rental Period
	1-6 Days	7-27 Days	28-60 Days
Class B	$27 per day	$162 for 7 days, +$25 for each additional day	$662 for 28 days, +$23 for each additional day
Class C	$34 per day	$204 for 7 days, +$31 for each additional day	$810 for 28 days, +$28 for each additional day
Class D	Class D cannot be rented for less than 7 days	$276 for 7 days, +$43 for each additional day	$1,136 for 28 days, +$38 for each additional day

The program asks the user to enter the rental period and type of car. The program then displays the appropriate cost. If a period longer than 60 days is entered, a message “Rental is not available for more than 60 days” is displayed. If a rental period of less than 6 days is entered for Class D, a message “Class D cars cannot be rented for less than 6 days” is displayed.