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    hi, i'm not sure where the starred line has come from, can anyone help? thank you
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    You have an equation for \frac{1}{2}y^2 involving c, and you know that c = \frac{1}{2} \ln 2, so substitute the expression for c in to eliminate it.
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    the RHS is just the same but subbing in the constant C and using log rules.
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    (Original post by Kolya)
    You have an equation for \frac{1}{2}y^2 involving c, and you know that c = \frac{1}{2} \ln 2, so substitute the expression for c in to eliminate it.
    isn't c=1/2 - ln2 ?

    i get

    y^2/2 = ln(1+e^x) + 1/2 - ln2

    which is close but not the same
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    (Original post by furryvision)
    isn't c=1/2 - ln2 ?

    i get

    y^2/2 = ln(1+e^x) + 1/2 - ln2

    which is close but not the same
    You're correct for c.
    Then use your laws of logs to combine the two log terms.
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    (Original post by Slumpy)
    You're correct for c.
    Then use your laws of logs to combine the two log terms.
    fab thank you, there's so many rules/laws i need to learn in the next 2 weeks!
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    (Original post by furryvision)
    fab thank you, there's so many rules/laws i need to learn in the next 2 weeks!
    No worries.
 
 
 
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Updated: August 6, 2009

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