Results 1 to 8 of 8

Math Help - Please help me with this differential calculus question?

  1. #1
    Newbie
    Joined
    Nov 2012
    From
    Hertfordshire
    Posts
    14

    Please help me with this differential calculus question?

    If the total cost (in s) function is given by
    TC = 2Q2 + 158Q - 12000

    where Q is the quantity produced

    (a) What Q would minimise total costs?
    Give your answer to 2 decimal places.

    (b) Use your value in (a) to find the minimum value for total costs.
    Give your answer to the nearest
    pound.


    Please show me how to get the answer. I would be extremely grateful. Thank you.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Jun 2012
    From
    AZ
    Posts
    616
    Thanks
    97

    Re: Please help me with this differential calculus question?

    Set the derivative to zero to find critical points

    \frac{d(TC)}{dQ} = 4Q + 158 = 0...this only makes sense if we can produce a negative amount. If we restrict Q to non-negative numbers, then Q = 0 minimizes cost, which turns out to be negative 12000. (also doesn't make much sense).
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Nov 2012
    From
    Hertfordshire
    Posts
    14

    Re: Please help me with this differential calculus question?

    thanks very much for the reply, its not 4Q though it's 2Q^2, I'm confused about what the answer is, will you please help me?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member
    Joined
    Jun 2012
    From
    AZ
    Posts
    616
    Thanks
    97

    Re: Please help me with this differential calculus question?

    Quote Originally Posted by Ceidon View Post
    thanks very much for the reply, its not 4Q though it's 2Q^2, I'm confused about what the answer is, will you please help me?
    Umm, what's the derivative of 2Q^2 with respect to Q?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Nov 2012
    From
    Hertfordshire
    Posts
    14

    Re: Please help me with this differential calculus question?

    Is the answer 0 for part A? Will you please help me with part B as well?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Newbie
    Joined
    Nov 2012
    From
    Hertfordshire
    Posts
    14

    Re: Please help me with this differential calculus question?

    Quote Originally Posted by richard1234 View Post
    Umm, what's the derivative of 2Q^2 with respect to Q?

    Sorry I got the question wrong it's

    TC = 2Q^2 - 158Q + 12000
    Follow Math Help Forum on Facebook and Google+

  7. #7
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    12,129
    Thanks
    1010

    Re: Please help me with this differential calculus question?

    please do not post the same problem twice in different forums.

    Please help me with this differential calculus question

    also, this is not a problem in differential equations.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Super Member
    Joined
    Jun 2012
    From
    AZ
    Posts
    616
    Thanks
    97

    Re: Please help me with this differential calculus question?

    Quote Originally Posted by Ceidon View Post
    Sorry I got the question wrong it's

    TC = 2Q^2 - 158Q + 12000
    See, this is why you should always double-check what you post...
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: December 8th 2012, 02:51 PM
  2. Replies: 1
    Last Post: March 12th 2012, 05:18 PM
  3. Replies: 2
    Last Post: October 21st 2009, 05:44 PM
  4. differential calculus
    Posted in the Calculus Forum
    Replies: 4
    Last Post: January 21st 2008, 07:24 PM
  5. Differential Calculus
    Posted in the Calculus Forum
    Replies: 1
    Last Post: May 2nd 2007, 08:11 AM

Search Tags


/mathhelpforum @mathhelpforum