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July 22, 2014

July 22, 2014

Posted by **Yoona** on Sunday, December 18, 2011 at 11:28pm.

so I did V=lhw

and found l=4-2h and w=3-2h

I also distributed them in the equation

I found V= and found the derivative

v'=12-28h+12h^2 and I set it equal to zero

from there...I dont know whay to do.

- calculus -
**Damon**, Monday, December 19, 2011 at 1:48amv= h (4-2h)(3-2h) = h (12 - 14 h + 4 h^2)

v = 12 h - 14 h^2 + 4 h^3

0 = 12 - 28 h + 12 h^2 agreed now factor 4 out

3 h^2 -7 h + 3 = 0

h = [ 7 +/- sqrt(49 - 36) ]/6

= [ 7 +/- sqrt(13)]/6

= 1.77 or .566

1.77 is more than half the width of 3 so is no good

use h = 0.566

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