Results 1 to 2 of 2

Math Help - Reasoning and graph problem

  1. #1
    Member
    Joined
    Sep 2009
    Posts
    145

    Reasoning and graph problem

    The price of a certain item was $10 in 1990 and it has gone up by $2 per year since 1990. If this trend continues, in what year will the price be $100?

    On average the price increased $2, so \frac{100 - 10}{2} = 45
    Hence 45 + 1990 = 2035


    Graph
    The figure above shows the graph of a quadratic function in the xy-plane. Of all the points (x, y) on the graph, for what value of x is the value of y greatest?

    Somewhere between 3 and 7? Does it have to be a particular point between 3 and 7?
    Perhaps I'm plain wrong?!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,829
    Thanks
    123
    Quote Originally Posted by Hellbent View Post
    The price of a certain item was $10 in 1990 and it has gone up by $2 per year since 1990. If this trend continues, in what year will the price be $100?

    On average the price increased $2, so \frac{100 - 10}{2} = 45
    Hence 45 + 1990 = 2035


    Graph
    The figure above shows the graph of a quadratic function in the xy-plane. Of all the points (x, y) on the graph, for what value of x is the value of y greatest?

    Somewhere between 3 and 7? Does it have to be a particular point between 3 and 7?
    Perhaps I'm plain wrong?!
    1. The graph of a quadratic function is symmetric. The vertex (that's the maximum or minimum point of the graph) is located on the axis of symmetry.

    2. Therefore the axis of symmetry bisects the distance between the zeros which will yield the x-coordinate of the maximum point.
    The x-coordinate is the mean of the 2 zeros. With your example x = 5.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. help with a reasoning problem.
    Posted in the Geometry Forum
    Replies: 3
    Last Post: February 27th 2011, 05:20 AM
  2. Reasoning word problem
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: September 22nd 2010, 10:19 PM
  3. Reasoning Problem
    Posted in the Algebra Forum
    Replies: 5
    Last Post: March 27th 2010, 02:54 AM
  4. Help solving and reasoning a word problem.
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 3rd 2008, 09:01 PM
  5. Inequality and Reasoning problem
    Posted in the Calculus Forum
    Replies: 6
    Last Post: November 16th 2007, 04:00 PM

Search Tags


/mathhelpforum @mathhelpforum