Word Problems/math

Advertisement


Question
a wire is 36 meter long is cut into two pieces, each piece is bent to form a rectangle which is 1 centimeter longer that its width. How long should each piece be to minimize the sum of the areas of the two rectangles?

Answer
Let x be the length of the first piece. The length of the second piece is 36-x meters.
For simplicity, let d = difference between length and width of rectangles = 1 cm = 0.01 m.

Calculate areas in terms of x and d.
Set the first derivative of total area to 0, then solve for x.

To minimize area of rectangles, both pieces should be 18 meters long.

http://www.flickr.com/photos/dwread/10747170045/
======
I double-checked it on a spreadsheet. Minimum total area when the pieces are 18 meters long  

Word Problems

All Answers


Answers by Expert:


Ask Experts

Volunteer


Janet Yang

Expertise

Word problems are my favorite type of math questions! I would not feel comfortable answering questions that require specialized knowledge (Physics, Statistics, etc.) because I have not studied these in depth.

Experience

I tutor students (fifth through twelfth grades) and am a Top Contributor on Yahoo!Answers with over 24,000 math solutions.

Publications
Co-author of An Outline of Scientific Writing: For Researchers With English as a Foreign Language.

Education/Credentials
I have a Bachelor's degree in Applied Mathematics from the University of California at Berkeley, and a Master of Business Administration degree from The Wharton School.

Past/Present Clients
George White Elementary School. Homework Help program at the Ridgewood Public Library, Ridgewood, NJ. Individual students.

©2016 About.com. All rights reserved.