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Need help on 2 optimization problems

  1. Nov 6, 2005 #1
    Question #1
    A printed page will have margins of 2 cm at the top and sides and 4 cm at the bottom. If the printed area is 150cm squared, find the dimentions of the whole page so that its area will be a minimum.

    Question #2
    Painters are painting the second floor exterior wall of the building that adjoins a busy sidewalk. A corridor 2m wide and 3 m high is built to protect pedestrians. What is the length of the shortest ladder that will reach from the ground over the corridor of the wall of the building?
  2. jcsd
  3. Nov 6, 2005 #2
    Ooh! Someone please answer this one. I have the same problems only with different numbers.
  4. Nov 6, 2005 #3
    i request to use calculus. take lenght as x-6. then solve for breadth dor he equation. report if you don't get after two days.
  5. Nov 7, 2005 #4


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    Science Advisor

    Have you done ANYTHING except just copy the problem down?

    1) Since you are asked for the dimensions of the page, let x= length, y= width of the page. What are the dimensions of the printed area?

    2) Draw a picture! Draw the corridor, seen from the end, as rectangle and draw the ladder just touching the outer corner. Do you see that the ladder forms the hypotenuse of a right triangle?
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