Lesson #82
The Spider and the Fly

Quote of the Day:
"The value of an education ... is not the learning of many facts but the training of the mind to think something that cannot be learned from textbooks."
-- Albert Einstein

Objectives:
The student will solve applied maxima/minima problems.

1. Collect Homework.

2. Prelude to the Spider and the Fly:
Materials Needed:
Big Screen TV set
string or tape measure

Problem: A bug on the back left corner of the TV crawls to the bottom right front corner. What is the shortest distance of its path?



Have students work on this problem to get an answer. Then discuss the answers. Show how to solve this max/min problem using a geometrical model:



The green path goes across the top and down the front of the TV. The red path goes across the top and down the side. Use the Pythagorean Theorem to solve the right triangles containing these lines:

So, the shortest distance is approximately 6.4'.

Now, measure the Big Screen TV with a piece of string or a tape measure. Put the string from corner to corner - it will minimize the distance naturally! Just another case where nature takes over in the minimization process.

3. Distribute a copy of the Spider and the Fly

4. Assignment:
Max/Min Review Puzzle

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Send any comments or questions to: David Pleacher