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Homework Help: Polynomial Problems

  1. May 4, 2004 #1
    Problem 5.
    An open box with a volume of 144cm^3 can be made by cutting a square of the same size from each corner of a square piece of tin 14cm on a side and folding up the edges of the tin. What is the length of a side of the square that is cut from each corner?

    Problem 24. Slove.
    f(x)=2x^3+9x^2+x-12
     
  2. jcsd
  3. May 4, 2004 #2
    V = lwh
    square piece of tin implies that length = width
    l = (14-z) where z is the amount cut
    V = h(14-z)^2
    144 = h(14-z)^2

    unless im missing something, you have 2 variables and one equation.. i dont think you can solve it..
     
  4. May 5, 2004 #3

    HallsofIvy

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    Science Advisor

    The height of the box IS z: when you fold the cut part up to form the sides, their height is the same as the length cut out:

    144= z(14-z)2.
     
  5. May 5, 2004 #4
    ah right, my mistake.
     
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