Results 1 to 3 of 3

Math Help - Help needed with Functions and Graphs

  1. #1
    Newbie
    Joined
    Jul 2010
    Posts
    3

    Help needed with Functions and Graphs

    Alright, the question is:

    Draw the graph of y = 3x + 60/x - 35.
    Range : x= 1.5 less than or equal to 10
    y= 9.5 to 1
    Find Gradient
    **Find solutions to the equation 4x + 60/x = 40 by drawing a suitable line.

    My attempted solution:

    Graph drawn,
    Gradient = 10
    ** i have solved the question ' Find solutions to the equation 4x + 60/x = 40 by drawing a suitable line.' by other means but i just do not know where to draw a straight line at. how does this relate to y = 3x + 60/x - 35 ??

    please help...

    kind regards
    tgpnlyt7095
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Dec 2009
    From
    1111
    Posts
    872
    Thanks
    3
    Quote Originally Posted by tgpnlyt7095 View Post
    Alright, the question is:

    Draw the graph of y = 3x + 60/x - 35.
    Range : x= 1.5 less than or equal to 10
    y= 9.5 to 1
    Find Gradient
    **Find solutions to the equation 4x + 60/x = 40 by drawing a suitable line.

    My attempted solution:

    Graph drawn,
    Gradient = 10
    ** i have solved the question ' Find solutions to the equation 4x + 60/x = 40 by drawing a suitable line.' by other means but i just do not know where to draw a straight line at. how does this relate to y = 3x + 60/x - 35 ??

    please help...

    kind regards
    tgpnlyt7095
    Dear tgpnlyt7095,

    y=3x + \frac{60}{x} - 35

    Since, 4x+\frac{60}{x}=40\Rightarrow{\frac{60}{x}=40-4x}

    Therefore, y=3x+40-4x-35\Rightarrow{y=-x+5}

    This is the straight line that you have to draw.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jul 2010
    Posts
    3
    Quote Originally Posted by Sudharaka View Post
    Dear tgpnlyt7095,

    y=3x + \frac{60}{x} - 35

    Since, 4x+\frac{60}{x}=40\Rightarrow{\frac{60}{x}=40-4x}

    Therefore, y=3x+40-4x-35\Rightarrow{y=-x+5}

    This is the straight line that you have to draw.
    Thanks a ton, you helped with the thinking process that i failed to deliver at just now .
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Functions and Graphs !
    Posted in the Algebra Forum
    Replies: 1
    Last Post: April 25th 2010, 12:59 AM
  2. Functions and graphs
    Posted in the Calculus Forum
    Replies: 3
    Last Post: January 16th 2009, 10:26 AM
  3. graphs of functions
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: October 25th 2008, 07:55 PM
  4. Functions and Their Graphs
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: July 17th 2008, 12:55 AM
  5. Functions and graphs...
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 26th 2006, 11:09 AM

Search Tags


/mathhelpforum @mathhelpforum