# Math Help - Evaluating a Logarithm

1. ## Evaluating a Logarithm

I'm having trouble evaluating this logarithm (I converted it to an exponential equation just to make it easier to read.)

3^y = pi

I've done a casual examination of the examples and problems I have (maybe 30 minutes of review) and I can't find an example where y isn't solvable by inspection.

2. ## Re: Evaluating a Logarithm

Originally Posted by bkbowser
I'm having trouble evaluating this logarithm (I converted it to an exponential equation just to make it easier to read.)

3^y = pi

I've done a casual examination of the examples and problems I have (maybe 30 minutes of review) and I can't find an example where y isn't solvable by inspection.

$3^y=\pi$

$\ln{3^y}=\ln{\pi}$

$y\ln{3}=\ln{\pi}$
.
.
.

3. ## Re: Evaluating a Logarithm

Oh I think I've just been insisting that the process is in the wrong section.

3^y = pi

y log 3 = log pi

so y = (log pi)/(log 3)?

4. ## Re: Evaluating a Logarithm

Originally Posted by Also sprach Zarathustra
$3^y=\pi$

$\ln{3^y}=\ln{\pi}$

$y\ln{3}=\ln{\pi}$
.
.
.

Ha, refresh failure. TYVM sir.

5. ## Re: Evaluating a Logarithm

Futher y = ln pi / ln 3 = ln pi - ln 3 if I am remembering correctly.

6. ## Re: Evaluating a Logarithm

Originally Posted by CalBear12
Futher y = ln pi / ln 3 = ln pi - ln 3 if I am remembering correctly.
Incorrect!

$\ln{\frac{a}{b}}=\ln{a}-\ln{b}$

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$\frac {\ln{ \pi}} { \ln {3} } = \log_3{\pi}$