Using the vi editor, write a C program on the Sun cluster that allows the user to choose from a menu of mathematical functions. Some of these functions will be standard C functions (see appendix B of the text), and some you will need to write yourself. After making a selection, the user should be prompted for whatever input is appropriate. Your program should then compute and display the appropriate result. This result should also be returned and stored in a variable, as one of the menu options should be to redisplay the result of the previous computation.

• The options in the menu should be:
  1. sine
  2. cosine
  3. exponentiation (power)
  4. factorial
  5. max
  6. sum
  7. redisplay the result of the last computation
  8. quit

  These options should be displayed as a numbered list, and the user should choose their selection by number.

• The menu may be displayed and the selection handled in the main program. However, for all of the options except redisplay and quit, your program must call a function to get the appropriate arguments from the user. This function then may compute the answer itself, or it may call another another function to do the calculation.
• The function associated with each menu option should return type double, and users should be permitted to enter values of type double in all cases except factorial. The statement for reading a double value into double variable dval is:

  scanf("%lf", &dval);

  The l is required, as "%f" will not work correctly. This statement will correctly read integer values into the double variable (i.e. the user does not have to enter 3.0, just 3). More detailed specifications for each function are:
  • sine, cosine: The user should be prompted for a double value. The sine (or cosine) of this value should be calculated, printed, and returned by the function.
  • exponentiation (power): The user should be prompted for two double values. If these values are base and exp, then the value of base (i.e. base to the exp power) should be calculated, printed, and returned by the function.
  • factorial: The user should be prompted for an integer, and the same error checking and computation as for the previous program should be done. The function should return a type double result.
  • max: The user should be prompted for three double values. The largest of the three should be determined, printed, and returned by the function.
  • sum: The user should be prompted for two integer values low and high. The value of:

    low + (low + 1) + (low + 2) + ... + (high - 1) + high

    should be computed, printed, and returned by the function. If low high, the value computed should be low.

  In all cases, you can assume that the user will not enter anything except an integer or a double, as appropriate.

• To hand in:
  • Either turn in a print out of your source code, or email me (wahls@psu.edu) the file containing your source code. If you email me the program, I will email you your score and any comments on your program sometime after the due date. I will also save a copy of your program to prevent later disputes.
  • Your code will be graded on correctness, readability, the clarity of messages printed for the user and appropriate use of comments.

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