# Rectangular container optimization

1. Apr 8, 2010

### hks118

1. The problem statement, all variables and given/known data
A rectangular storage container with an open top is to have a volume of 10 m^3. The length of this base is twice the width. Material for the base costs $10 per square meter. Material for the sides costs$6 per square meter. Find the cost of materials for the cheapest such container.

2. Relevant equations

See below

3. The attempt at a solution
I have my worked out (but wrong) solution here: http://img510.imageshack.us/img510/7963/calchw.jpg [Broken]
For some reason I keep getting a negative answer. I really have no idea what I'm doing wrong.

Last edited by a moderator: May 4, 2017
2. Apr 9, 2010

### hotvette

Your expression for y in terms of x isn't correct.