Results 1 to 4 of 4

Math Help - absolute maximum and minimum

  1. #1
    Newbie
    Joined
    Nov 2009
    Posts
    21

    absolute maximum and minimum

    I have one more of these problems that I got stuck on:

    Help Plz?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member
    Joined
    Mar 2009
    Posts
    378
    What have you done so far?

    You take the derivative and set it to zero. Solve for x, this will give you all critical points. From here you can look at the second derivative at those points to determine if they are maximums or minimums. If \frac{d^2f(x)}{dx^2} < 0 then the point is a maximum. If \frac{d^2f(x)}{dx^2} > 0 then the point is a minimum. If \frac{d^2f(x)}{dx^2} = 0 then the point is a neither. Don't forget to determine the value f(x).
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Nov 2009
    Posts
    21
    thats the problem, I know I don't have the right derivative. We are just learning them, and Im not sure how to do it. After I get the derivative I'm fine, but I need help with getting that.

    I know that after I set my values equal to zero, I just take those values and plug them in the derivative.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Senior Member
    Joined
    Mar 2009
    Posts
    378
    Okay, you will use the quotient rule, i.e.,
    f'(x) = \frac{\frac{d}{dx}\left[-x^3 + x^2 + 3x + 1\right]\cdot (x+1) + \frac{d}{dx}\left[x+1\right]\cdot (-x^3 + x^2 + 3x + 1)}{(x+1)^2}.
    Can you take it from here?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 8
    Last Post: May 23rd 2010, 10:59 PM
  2. absolute maximum and minimum help
    Posted in the Calculus Forum
    Replies: 1
    Last Post: December 6th 2009, 10:22 AM
  3. finding absolute maximum and absolute minimum
    Posted in the Calculus Forum
    Replies: 1
    Last Post: November 15th 2009, 04:22 PM
  4. Replies: 2
    Last Post: November 8th 2009, 01:52 PM
  5. Find the absolute maximum and absolute minimum
    Posted in the Calculus Forum
    Replies: 5
    Last Post: December 12th 2008, 09:46 AM

Search Tags


/mathhelpforum @mathhelpforum