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Plotting Two Variables

  1. Sep 21, 2012 #1
    Hi,

    The question is the following:

    Another student proposes that c is proportional to d0.5 State a suitable graph that can be plotted to test this proposal.

    I suggested plotting log c = 0.5 log d.

    One of the answers the markscheme accepts is log c = log d

    Can anyone tell me why my answer is wrong?

    Thanks!
     
  2. jcsd
  3. Sep 22, 2012 #2
    Inversely proportional or directly proportional ?

    Is c directly proportional to d1/2 ? If so , then equation cannot be log c = 0.5 log d.

    Anyways what's precisely is question asking for ? Your answer seems to be wrong because you missed the constants involved in proportionality.
     
  4. Sep 22, 2012 #3
    It is supposed to be directly proportional I guess, since they want a straight line through the origin.

    I just don't understand how you can get lg c = lg d like the mark scheme asks for
     
  5. Sep 22, 2012 #4

    Redbelly98

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    The mark scheme appears to be wrong. Perhaps the person who wrote it accidentally left out the 0.5 factor.
     
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