# Lograthmic function

1. Jan 27, 2006

### jacy

Hello,
Am trying to solve this natural log problem, where i have to find the value of x.

ln (3+x)=7

this is what i have done

3+x= e7
x= 1093.63

This is the answer am getting, but its wrong. Can someone please let me know what am doing wrong, thanks.

2. Jan 27, 2006

### TD

Well the answer isn't 'wrong', but it's only an approximation, why not leave it as an exact answer? It seems that your method was ok...

$$\ln \left( {3 + x} \right) = 7 \Leftrightarrow 3 + x = e^7 \Leftrightarrow x = e^7 - 3 \Leftrightarrow x \approx 1093.633158 \ldots$$

So instead of doing that last stap (see how I didn't the equality sign?) just leave it as $x = e^7 - 3$.

3. Jan 28, 2006

### jacy

Thanks for ur help.

4. Jan 29, 2006

### TD

You're welcome