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Homework Help: More A2 Help

  1. Oct 26, 2006 #1
    There are two more problems I am unsure of, so if someone could just check my answers, I'd be grateful.

    Suppose y=4/x.
    a) Find the rate of change from x=1 to x=2
    b) Find the rate of change from x=2 to x=3
    c) Why are a and b not equal?

    a) -2
    b) -2/3
    c) It is a hyperbola

    Suppose [tex]s=16d^2[/tex]
    a) How does the value of s change if d is doubled?
    b) How does the value of s change if d is divided by 3?

    a) s is multiplied by 2
    b) s is divided by 3
    Last edited: Oct 26, 2006
  2. jcsd
  3. Oct 26, 2006 #2
    Problem 1 is correct

    Problem 2 is incorrect. just look at d = 1. Since it is a squared term it would be multiplied by 4. And if it is divided by 3 S is (1/3)^2 = 1/9 S.
    Last edited: Oct 26, 2006
  4. Oct 26, 2006 #3
    Oh ok, I disregarded the square part. And you would still divide by 1/9 in part b, right? So the answer would be "s is divided by 1/9?"
    Last edited: Oct 26, 2006
  5. Oct 26, 2006 #4
    For your answer in (b) it would be divided by 9. Again this is because we have a squared term. If [tex] s = 16d [/tex] then it would be divided by 3 because of the linear term. And s would also be multiplied by 2 if we had the linear term.
  6. Oct 26, 2006 #5
    no S would be divided by 9
  7. Oct 26, 2006 #6
    Sorry, I hadn't read your second post before I edited mine.
    And I get it it now. Thank you for your help!
    Last edited: Oct 26, 2006
  8. Oct 26, 2006 #7
    Cool! But I'm confused...how do you know I like it?
  9. Oct 26, 2006 #8
    Lol ok that makes sense! I use pretty much the same username for every site I'm on. Is courtigrad your name on youtube, too?
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