The inexactness that results from doing numerical computations with
floating point numbers often results in much more than a mistake at the
last decimal point. If you're not careful, large errors can occur at
crucial points in the calculation that result in your answer being
completely wrong.
If you are careful, though, most engineering problems can be adequately
solved with the 6 digit floating numbers that Mathematica provides by
default. In fact, most engineering problems can be solved with smaller
floating point numbers. The reason is that very few physical
measurements can be made with such accuracy. In view of this,
Mathematica will allow you to change the size of the floating point
numbers that it uses.
In this set of exercises, you will use Mathematica to investigate the
points that we made in the last two paragraphs.
The exercises contain five questions, numbered in sequence and
displayed in boldface type. You are to prepare a short report giving
the answers to these questions. For each question, your report should
contain the text of the question as given below, your answer to the
question, and the output from Mathematica that shows how you arrived
at your answer.
To prepare this report, you will need to save your Mathematica session
to a file as described earlier in this lesson. Save it to a file
called hw.txt. Then read the file into a text editor and edit it by
removing the extraneous parts of the Mathematica session and adding our
questions and your commentary. You will doubtless want to use the
mouse to copy and paste the questions from the notebook into the text
file.
Joseph Zachary and Thomas L. Marchioro