Results 1 to 2 of 2

Math Help - maximum profit? quadratic function??

  1. #1
    Newbie
    Joined
    Aug 2010
    Posts
    21

    Exclamation maximum profit? quadratic function??

    I'm quite confused on this word problem.... I know I have to complete the square, right? But, I'm not certain:



    please also supply work! i have many more questions like this and shall use this one as a template to solve the rest!


    thank you so much!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,807
    Thanks
    116
    Quote Originally Posted by lollilikeslife View Post
    I'm quite confused on this word problem.... I know I have to complete the square, right? But, I'm not certain:



    please also supply work! i have many more questions like this and shall use this one as a template to solve the rest!


    thank you so much!
    The given function P is a parabola opening down. Therefore the absolute maximum is at it's vertex.

    I don't know which method you prefer to determine the vertex, but since you mentioned completing the square, here we go:

    P(x)=-0.5x^2+20x+230=-0.5(x^2-40x+400-400)+230

    \ \ \  =-0.5(x-20)^2+200+230 = \boxed{-0.5(x-20)^2+430}

    Thus the maxium is 430 at x = 20
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 14
    Last Post: May 7th 2011, 05:58 PM
  2. Maximum profit.
    Posted in the Calculus Forum
    Replies: 5
    Last Post: November 3rd 2010, 09:27 AM
  3. Maximum Profit
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 15th 2010, 11:39 AM
  4. Maximum profit questions
    Posted in the Calculus Forum
    Replies: 4
    Last Post: May 14th 2009, 05:44 PM
  5. Maximum profit
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 22nd 2009, 04:33 AM

Search Tags


/mathhelpforum @mathhelpforum