Results 1 to 6 of 6

Thread: Linear Equation

  1. #1
    Senior Member
    Joined
    Mar 2012
    Posts
    348
    Thanks
    4

    Linear Equation

    Pharmacological products must specify recommended dosages for adults and children. Two formulas for modification of adult dosages levels for young children are

    Cowling's rule: y = (1 / 24) (t + 1)a
    Friend's rule: y = (2 / 25)ta

    where a denotes the adult dose (in milligrams) and t denotes the age of the child (in years).

    (a) If a = 100, graph the two linear equations on the same axes for 0 <= t <= 12.

    (b) For what age do the two formulas specify the same dosage?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    12,713
    Thanks
    1882

    Re: Linear Equation

    Well have you graphed the functions yet?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Mar 2012
    Posts
    348
    Thanks
    4

    Re: Linear Equation

    I got 2 parallel Lines.

    First Equation
    t 0 1 2
    y 25/6 25/3 25/2

    Second Equation
    t 0 1 2
    y 0 8 16
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member
    Joined
    Jun 2014
    From
    Britain
    Posts
    27
    Thanks
    6

    Re: Linear Equation

    Hi

    I would tackle the graph plotting by taking t = 0 and t = 12 and calculate the yc and yf values as below -

    t : 0 12
    yc : 25/6 25.13/6 (this is < 72 so these lines must cross)
    yf : 0 72

    I don't think these are actually parallel although they may look so over a smaller range.

    Regards
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor
    Joined
    Nov 2013
    From
    California
    Posts
    4,939
    Thanks
    2067

    Re: Linear Equation

    Quote Originally Posted by joshuaa View Post
    I got 2 parallel Lines.

    First Equation
    t 0 1 2
    y 25/6 25/3 25/2

    Second Equation
    t 0 1 2
    y 0 8 16
    $a=100$

    $y_c(t)=y_f(t)$

    $\dfrac {100(t+1)}{24}=\dfrac{200 t}{25}$

    $2500(t+1)=4800t$

    $2500=2300t$

    $t=\dfrac {25}{23}$

    not really that big a deal
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Senior Member
    Joined
    Mar 2012
    Posts
    348
    Thanks
    4

    Re: Linear Equation

    Thank You. It was helpful.

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Converting a Vector equation to a linear equation
    Posted in the Advanced Algebra Forum
    Replies: 7
    Last Post: Mar 8th 2013, 10:52 PM
  2. Replies: 4
    Last Post: Mar 14th 2012, 08:21 AM
  3. linear equation help
    Posted in the Advanced Algebra Forum
    Replies: 5
    Last Post: Dec 2nd 2009, 07:34 AM
  4. linear equation
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: Oct 22nd 2009, 11:26 AM
  5. Replies: 1
    Last Post: Nov 17th 2008, 07:17 PM

Search Tags


/mathhelpforum @mathhelpforum