Saturday

December 20, 2014

December 20, 2014

Posted by **kim** on Sunday, April 29, 2012 at 6:39pm.

- precalculus -
**Steve**, Sunday, April 29, 2012 at 6:50pmv = x(14-2x)(27-2x)

dv/dx = 2(6x^2 - 82x + 189)

dv/dx=0 when x = (41 ± √547)/6 = 2.93, 10.73

knowing the shape of cubics, you should have no trouble "differentiating" the max from the min.

- precalculus -
**Damon**, Sunday, April 29, 2012 at 6:57pmlength = z = 27 -2x

width = y = 14 - 2x

v = (27-2x)(14-2x)x

v = ( 378 - 82 x + 4 x^2 ) x

v = 378 x -82 x^2 + 4 x^3

max when dv/dx = 0

dv/dx = 378 - 164 x + 12 x^2 = 0

6 x^2 - 82 x + 189 = 0

x = [ 82 +/- sqrt (6724-4536) ]/12

x = [82 +/- 46.8 ]/12

x = 10.7 too big, negative width

x = 2.93 inches

**Answer this Question**

**Related Questions**

calculus optimization problem - by cutting away identical squares from each ...

calc - by cutting away identical squares from each corner of a rectangular piece...

Calculus - A box with an open top is to be made from a square piece of cardboard...

calculus - an open rectangular box is to be made from a piece of cardboard 8 ...

math - A box with an open top is to be constructed from a rectangular piece of ...

Precalculus - From a rectangular piece of cardboard having dimensions a × b, ...

math - a piece of cardboard is twice as it is wide. It is to be made into a box ...

Algebra - A box with no top is to be constructed from a piece of cardboard ...

math - open top rectangular box made from 35 x 35 inch piece of sheet metal by ...

Engineering - A box with an open top is to be made from a square piece of ...