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# Question About Logarithms! Watch

1. Ok:

P = a x 10^-kt

I get I'm meant to take logs of this but I'm not sure how with that times sign in there.

I get logP = loga x -kt (because log10 is 1) but it's

logP = loga - kt

Can someone explain to me where this comes from please! Thanks

The question paper is January 2011
2. (Original post by 3607)
...
You need to familiarise yourself with the rules for manipulating logs:

Log (a x b) = log a + log b
3. Oh wow I know that as well awful mistake to make haha.

Horribly nooby thing I did

I did log(a x 10^-kt)

then just expanded it like you normally would -.-

Thanks dude, will help me on friday
4. (Original post by 3607)
Thanks dude, will help me on friday
np. Good luck.

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