# Thread: Solving an Exponetial & Log Equation.

1. ## Solving an Exponetial & Log Equation.

Okay, so here is what I have $P=1045ln(0.0016f+1)$

P= perceived pitch (mels), F= frequency (hertz)

I need to solve when P= 1500 algebraically.

Can anyone give me some sparks to start my engine? Thanks.

2. Hello,

Well, divide each side of the equation by 1045, then take the exponential of the two sides, and ...

3. Originally Posted by Moo
Hello,

Well, divide each side of the equation by 1045, then take the exponential of the two sides, and ...
Well after doing that and reducing I got: $\frac{300}{209}=ln(.0016f+1)$ I don't know how to break up the ln part. Do I need it in log for like $\frac{300}{209}=\frac{log(.0016f+1)}{log(e)}$ but still I don't know how to break apart the $log(.0016f+1)$

4. If ln is the neperian one :

$\ln(0.016f+1)=300/209 \Longleftrightarrow 0.016f+1=e^{300/209}$

If it's the logarithm in basis 10 :

$\ln(0.016f+1)=300/209 \Longleftrightarrow 0.016f+1=10^{300/209}$

5. I confused, I can't see how I get the answer because when I find the answer using my calculator I get approx:1278.84

6. I should have added "then, isolate f "

7. Originally Posted by Moo
I should have added "then, isolate f "

I am trying to think but I just can't figure it out.