Wednesday

December 17, 2014

December 17, 2014

Posted by **eve** on Saturday, March 16, 2013 at 9:42pm.

- calculus -
**Reiny**, Saturday, March 16, 2013 at 9:51pmThe the side of the cut-out square be x inches

base of box = 14-2x by 6-2x

(clearly x < 3 )

volume = V = x(14-2x)(6-2x)

= 84x - 40x^2 + 4x^3

dV/dx = 84 - 80x + 12x^2

= 0 for a max V

divide by 4

3x^2 - 20x + 21 = 0

x = (20 ± √148)/6

= 5.36 or 1.306 inches, but remember x < 3

so x = 1.31 correct to 2 decimals

check: pick a value slightly greater and slightly less than our answer

let x = 1.3 , V = 1.3(14-2.6)(6-2.6) = 50.388

let x = 1.31 , V = 1.31(14-2.62)(6-2.62) = 50.38836

let x = 1.4 , V = 1.4(14-2.8)(6-2.8) = 50.176

x = 1.31 yields the greatest volume

- calculus -
**Riley**, Wednesday, April 10, 2013 at 10:55pmThe demand function for a certain make of replacement cartridges for a water purifier is given by the following equation where p is the unit price in dollars and x is the quantity demanded each week, measured in units of a thousand.

-0.01x^2-0.3x+19

Determine the consumers' surplus if the market price is set at $1/cartridge. (Round your answer to two decimal places.)

- calculus -
**Eve**, Tuesday, September 17, 2013 at 5:35pmFind the point on the graph where the tangent line is horizontal.

x/(x^2+25)

I know you have to do the quotient rule to find the derivative of the function, but I do not know what to do after that.

**Answer this Question**

**Related Questions**

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

Calculus - By cutting away identical squares from each corner of a rectangular ...

math - By cutting away identical squares from each corner of a rectangular ...

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

Math - A box with an open top is to be made by cutting 5-inch squares from the ...

PRE-CALCULUS - AN OPEN BOX IS FORMED BY CUTTING SQUARES OUT OF A PIECE OF ...

math - An open box is made from a rectangular piece of cardboard, with ...

Calculus - an open box is made by cutting out squares from the corners of a ...

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

math - An open-topped box is made from a rectangular piece of cardboard, with ...