Lesson 1c.
This Lesson asks you to think more carefully about one of the Problems from Lesson 1 and Lesson 1b.  The instructions from the first part of Lesson 1b are repeated below, with clarifications and emphases added in red font.

NOTE 1: Be sure to read  Homework Format  and Homework Writing Policy  BEFORE writing up your solutions to be turned in.

NOTE 2: When two or more Lessons are to be turned in on the same day, please staple the Lessons separately and turn them in separately. (E.g., if Lessons 1 and 2 are due the same day, turn in Lesson 1 separately from Lesson 2.)

Due Friday, June 27

1.3 Problem:
A few of the student solutions to Problem 1.7 had roughly the right idea of the reason for the given formula (1.3). None of the solutions really explained the formula in all cases. The point of the following questions is to encourage you to think more carefully about the issues connected with formula (1.3); it is not necessary to try to redo Problem 1.7:
  1. Use formula (1.3) to calculate carefully the number of days between March 15 and April 4, using the 30-day month convention. (“Calculate carefully” includes stating explicitly the values you use for the parameters  d1,  etc.) Show that your answer is reasonable for a “30-day month” in this particular case, and show how your answer differs from the actual number of days between the two given dates.

  2. Try to EXPLAIN WHY, in this case (i.e., in the specific example in Problem 1), the formula (1.3) gives the correct number of days between the two dates using the 30-day month convention. Although you should explain for this particular example, your explanation should try to understand WHY the formula works in the general case, for days other than March 15 and April 4.

  3. Now try to explain why formula (1.3) gives the correct number of days between two dates in the general case that
         y2 = y1;
         m2 = m1 + 1  (also, assume that  m1 ≥ 1  and  m2 ≤ 12,  if useful);
         d2 < d1.

    (Note that you are not asked to explain what THESE equations mean, although you will have to understand what they mean in order to answer the question. You are asked to explain why formula (1.3) gives the correct number of days between dates when these equations are satisfied, assuming a “30-day month”.)

NOTE: Be sure to read  Homework Format  and Homework Writing Policy  BEFORE writing up your solutions to be turned in.


NOTE: As stated on the Course Home Page, all due dates are tentative. Assignments, or parts of assignments, may be postponed to a later date.


Last modified Jun 21, 2008 10:44 PM

Go to Lesson 2.

Back to Course Home Page