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Homework Help: Need a check on a simple derivative question

  1. Oct 1, 2012 #1
    1. The problem statement, all variables and given/known data
    If f(t)=(4t+2)/(t+3) what is f'(t)=?

    3. The attempt at a solution
    I got 10/(t+3)^2 but my professor insists it is 6/(t+7)^2, I know this is a simple question but I don't know where I am going wrong.
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Oct 1, 2012 #2
    You are correct.
  4. Oct 1, 2012 #3


    Staff: Mentor

    The denominator in the derivative can't possibly be (t + 7)2. Make sure that you and your instructor are working the same problem.
  5. Oct 1, 2012 #4
    That's what I told him but he has a problem listening to anyone who doesn't have Phd after their name, this is going to be fun lol!

    Thanks for the verification!
  6. Oct 1, 2012 #5
    I often had a "fight" with my lecturers (many of whom were professors) at university and often came out on top.

    So please pursue this!

    In a calm manner, of course...
  7. Oct 1, 2012 #6
    Oh I'm going to pursue it, this is the 'fun' part of going back to school :)

    I've always been polite, although during the summer session one of my Professors asked me to please not sign up for any of his classes again, ha ha!
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