Sunday, February 22, 2009

The [] is used since subscript and superscript are not allowed.
2 [3] = 8 can also be expressed as log [2] 8 = 3
Is this correct?
0.035 [x] = 2.74
Find x?

Re-express as a log which is log [0.035] 2.74 = x

  1. Draw line
  2. log 2.74__ = x
    log 0.035
Or is this correct?
0.035 [x] = 2.74 Find x?

  1. Log both sides
  2. log 0.035 [x] = log 2.74
  3. Re-express to remove power
    x log 0.035 = log 2.74
  4. Make x the subject of the equation
    x = log 2.74 / log 0.035
Posted by at

11 comments:

  1. renjisanFebruary 26, 2009 at 12:03 AM

    the first method is correct but the second is wrong because i dont think u can jus log both sides like that because that would mean that its base 10

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  2. AnonymousFebruary 26, 2009 at 6:31 PM

    well the first method is correct but the second is wrong!!!!!!!!!!!!! This is because wen both sides are logged, log 0.035 [x]= log 2.74..............x is a base in this eq'n, so it cannot be made the S.O.F. in this eq'n...............the only way x cud become the S.O.F. in a logs problem is if u got a problem like dis:

    5^x= 15

    now logging both sides of the eq'n gives:

    log 5^x= log 15

    So x.log 5= log 15

    x = log 15/log 5.

    So x cud only become the S.O.F. wen it is written as an EXPONENT!!!!!!! (POWER; INDEX)

    ReplyDelete
  3. renjisanFebruary 27, 2009 at 3:02 AM

    well lets hope that someppl dont go and nake that same mistake we're seeing here because is really easy tuh jus log both side and you wud feel its right because it looking nice and thats is tru

    ReplyDelete
  4. Low riderFebruary 28, 2009 at 9:40 AM

    I agree the first method is correct.And according to renjisany to make a mistake like that.

    ReplyDelete
  5. brainiacMarch 2, 2009 at 4:58 AM

    i also agree that the first method is correct.
    i myself also hope that i don't make that mistake cuz according to renjisan it lookin nice and correct!!!!

    ReplyDelete
  6. mysticwings*March 2, 2009 at 3:54 PM

    i think both methods are correct because in the first method a division line can be used. in the second method both sides can be logged because there are single terms on each side. ie there isnt any terms seprated by opperation signs!

    ReplyDelete
  7. fariel'sbeststudentMarch 3, 2009 at 8:54 AM

    This comment has been removed by the author.

    ReplyDelete
  8. gunironMarch 4, 2009 at 5:36 PM

    i agree with the first method of the solution. you draw the line to change the whole log expression to base ten so you can use your calculator and jus work it out

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  9. gunironMarch 4, 2009 at 5:39 PM

    the second solution is wrong because the 0.035 is the base of the whole expression. its not a term being multiplied by another term

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  10. SexyloveMarch 14, 2009 at 11:41 AM

    I agree that the first method is correct...and the second is wrong. For the second one, just logging both sides will result in the same answer as the first...but de pt here is the method of working...and from there we will have to use it as base 10...mistakes like dis can occur ..

    ReplyDelete
  11. Low riderMarch 21, 2009 at 7:48 AM

    Thinking about it the two ways look correct. Ain,t you should get the same answer. Can anyone verify this with me?

    ReplyDelete

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