1. Write a program to swap three integer variable values (a to b, b to c, c to a).
 
2. Write a program that takes two rational numbers from the user and adds them. Display the result as a real number on the screen. You will read 4 integers from the user, first two will form the first rational number and last two will form the second rational number. (Example: if the user enters 6 8 12 5, your rational numbers are 6/8 and 12/5). If the user enters 0 for the second or fourth number, then you will display a warning message on the screen and finish the program. 
 
soln: (do not forget the integer division property)
scanf("%d%d%d%d", &num1, &num2, &num3, &num4);
result = ((double) num1 / num2) + ((double) num3 / num4);
 
3. Differentation: Differentatiate a given polynomial. (max degree 3). User will enter the degree of the polynomial and the coefficients and you will display the original and differentiated version on the screen 
(Hint: dont forget that the number of coefficients is one more than the degree of the polynomial)
exp:
Enter the degree: 3
Enter the coefficients: 3 5 12 4
Original polynomial: 3x^3 + 5x^2 + 12x + 4
Differentiation: 9x^2 + 10x + 12