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Homework Help: Simplifying Expression using Logarithms

  1. Jun 12, 2010 #1
    Simplify the attached expression using any relevant logarithmic rules

    I havent really done much with logarithms, so i didnt know where to start?
     

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  3. Jun 12, 2010 #2

    rl.bhat

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    Given problem can be written as

    log(2)4 + log(16)1/4 + log(1/4)2 - log(7/4)

    Now use laws of logarithm to simplify.
     
  4. Jun 12, 2010 #3
    the problem is I dont know how to do that?
     
  5. Jun 12, 2010 #4

    rl.bhat

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    log(a) + log(b) = log(ab)

    log(a) - log(b) = log(a/b)
     
  6. Jun 12, 2010 #5

    HallsofIvy

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    Then you should start by learning the "relevant logarithmic rules"!

    [itex]log(ab)= log(a)+ log(b)[/itex]

    [itex]log(a/b)= log(a)- lob(b)[/itex]

    [itex]log(a^b)= b log(a)[/itex]
     
  7. Jun 12, 2010 #6
    Can somebody please demonstrate the question?
     
  8. Jun 12, 2010 #7
    No, you need to solve it yourself; you received sufficient help in the previous posts. Follow that advice.
     
  9. Jun 12, 2010 #8
    That advice dosent get me anywhere!
     
  10. Jun 12, 2010 #9
    Post what you have tried so far pertaining to the advice, or post and ask a question regarding the advice. If I asked you to simplify log(a) + log(b), how would you do it?
     
  11. Jun 12, 2010 #10
    well that would be log(ab)
     
  12. Jun 12, 2010 #11
    Yes, so look at the 3 logarithm rules provided by HallsofIvy and apply them to your problem.
     
  13. Jun 12, 2010 #12
    ok so I'm up to log(2^2) + log(16^1/4) + log(1/4^2) - log(7/4)
     
  14. Jun 12, 2010 #13
    Instead of log(22) it should be something else. Now, continue until you get an expression with only one log.
     
  15. Jun 12, 2010 #14
    yes ok it would be log(2^4), but then I realy am stuck on what to do next!
     
  16. Jun 12, 2010 #15
    Follow your own advice. :wink:
     
  17. Jun 12, 2010 #16
    I dont know how to!!!!!!
     
  18. Jun 12, 2010 #17

    rl.bhat

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    OK.

    What is 24, 161/4 and 42?

    Substitute these values in my post #2 and simplify by using the relevant equation given by us.
     
  19. Jun 12, 2010 #18
    Would the answer be log(2/1.75)
     
  20. Jun 12, 2010 #19
    Ok, now I have one which is attached.
    I have managed to get to this
    logx4/logx1/3
    What do I do from here?
     

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  21. Jun 12, 2010 #20
    Or would it be 12logx? I dont know.
     
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