DANVILLE AREA COMMUNITY COLLEGE
INTRODUCTION TO COMPUTER SCIENCE
MATH 110,    Fall 2008

Homework 2  (Due Sept. 4 in class)

Read: Section 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 2.10, 2.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.18, 2.19, 2.20, 2.21;
                 Pay special attention on 2.5, 2.6, 2.7, 2.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.18, 2.19;
                 Understand the 12 examples in Chapter 2 by compiling and running them.

Solve the following Problems:

Problem (2-45):  (p. 153);
Problem (2-46):  (p. 153);
Problem (2-54):  (p. 155).  (will be continued on HW-3)

Hint:  (you don't have to follow this hint if you can solve these problems)

Exercise 2.45:

(1) Read Section 2.14 and 2.15.
(2) Run fig02_20.cpp on page 96. and try to understand this example completely.
(3) Modify fig02_20.cpp, and let it print out the sum of 1, 2, 3, 4, and 5. and then save this new version on disk.
(4) Study Problem 2.42 on page 153, and then use a nested for structure on your new version,  let it print out:
      table as follows:
        x,                sum,
        5                sum of 1, 2, 3, 4, and 5.
        4                sum of 1, 2, 3, 4.
        3                sum of 1, 2, 3.
        2                sum of 1, 2.
        1                sum of 1.
(5)  After you finish this, simply change your sum to production.
(6)  The following  is a suggestion to calculat the factorial of 10,  (10*9*8*7*6*5*4*3*2*1):
           for ( int j = 1; j <= 10; ++j )
              factorial *= j;
                 cout << factorial;

Exercise 2.46:

(1) Read Section 2.14 and 2.15.
(2) Run fig02_21.cpp on page 98. and try to understand this example completely.
(3) Modify fig02_21.cpp, change rate from 0.05 to a integer 5,
         (in order to get the correct results, line 31 should change to "rate/100.0" accordingly.
(4) Study Problem 2.42 on page 153, and then use a nested for structure on your new version,  Your outer loop is
        rate = 5; rate <= 10; rate++ .

Exercise 2.54:
To learn a general procedure how to solve a relatively complicated problem,
here are some suggestions (you do NOT have to follow).
(1) Write a simple program to calculate the Pi (use for structure), print the first 5 terms.
        Then use a calculator to check your results.
(2) Write a simple program to calculate the Pi (use for structure), print the first 10 terms.
        Then use a calculator to check your results.
(3) After you got a dependent program, then try a few large i.  We will continue working on 2.54
        in HW-3 to answer all the questions of 2.54.
(4) To get a positive and negative terms you may try this (there are many methods):
        for(float a=1; a<=999999;a+=2)
        {p+=x*(4/a);
        x*=-1; }

SAVE YOUR WORK ONTO TWO DIFFERENT DISKS.

The computer unit of DACC  will "clean up" all the PC's in MMC-206 every week.
If you don't save your work to the disk, you will lose everything you did.

Exam-1 on Sept. 11  (covers Chapter 1 and 2).
Prepare your Exam-1 by doing:
            (a) review problem input 4 different integers from the key board,
                  then, print out the largest one on the screen.
            (b) review the problems on page 50 to 55.