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# Logs question? (C4)

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1. How do you make T the subject in this equation?

ln2 + (T-10)lnp = Tlnq
2. (Original post by Phoebus Apollo)
How do you make T the subject in this equation?

ln2 + (T-10)lnp = Tlnq
First put evverything involving T one one side, so:

You can simplify using the addition/subtractin rules for logarithms, i.e: . Then divide by the coefficient of to get it alone.
3. (Original post by Phoebus Apollo)
How do you make T the subject in this equation?

ln2 + (T-10)lnp = Tlnq
Next step: ln2 + T*lnp - 10*lnp = Tlnq
then, T*lnq + T*lnp = ln2 + 10*lnp
so, T*ln(q/p) = -ln(10^p/2)
finally, T= -ln(10^p/2) / ln(q/p)
5. (Original post by Bath~Student)
Next step: ln2 + T*lnp - 10*lnp = Tlnq
then, T*lnq - T*lnp = ln2 + 10*lnp
so, T*ln(q/p) = ln(10^p/2)
finally, T= ln(10^p/2) / ln(q/p)
Bolded the incorrect bits.
6. (Original post by Zacken)
Bolded the incorrect bits.
Oh, that's disgusting.

That's what comes from trying to beat you, that one addicted, self-declared genius who dwells here, day and night.
7. (Original post by Bath~Student)
Oh, that's disgusting.

That's what comes from trying to beat you, that one addicted, self-declared genius who dwells here, day and night.
Cheers.
8. (Original post by Zacken)
First put evverything involving T one one side, so:

You can simplify using the addition/subtractin rules for logarithms, i.e: . Then divide by the coefficient of to get it alone.
(Original post by Bath~Student)
Next step: ln2 + T*lnp - 10*lnp = Tlnq
then, T*lnq + T*lnp = ln2 + 10*lnp
so, T*ln(q/p) = -ln(10^p/2)
finally, T= -ln(10^p/2) / ln(q/p)
Thanks!

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