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C1 indices

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    (Original post by tnetennba)
    You could use logarithms:
    Log 4^x = Log 0.25
    x Log 4 = Log 0.25
    x= (Log 0.25)/(Log 4)
    x=-1
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    Make them both to the base of 2 and then equate the indices...

    4 ^ x = 2^2x
    1/4 = 2^-2

    2^2x = 2^-2

    equate both indices...
    2x = -2
    x = -1

    In conclusion: Equate both bases and then equate the indices and simplify.
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    (Original post by Waqar.)
    Make them both to the base of 2 and then equate the indices...

    4 ^ x = 2^2x
    1/4 = 2^-2

    2^2x = 2^-2

    equate both indices...
    2x = -2
    x = -1

    In conclusion: Equate both bases and then equate the indices and simplify.
    The bases are fine as it is, I don't see why you are changing it to 2. It's quite easy to see it using the base 4.
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    (Original post by raheem94)
    ln is in C3, while OP is studying C1 so she probably doesn't knows logarithms.
    Fair enough, if I'm honest I'm not 100% clear on what's covered in each module having done a different specification.
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    (Original post by jessica_anne_clu)
    but how would you go about it? I know the answer is -1 but I don't know how you'd get it
    You can show it using the ln rule however you apparently haven't been taught it yet so the other method would be comparing powers (make sure the base on both sides are equal).

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Updated: March 16, 2012
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