# Log rules

1. Jun 11, 2009

### Fairy111

1. The problem statement, all variables and given/known data

If you have a.log(b)+ c.log(d), is that equal to,

(a+c)log(bd) or (a.c)log(bd) ?

2. Relevant equations

3. The attempt at a solution

2. Jun 11, 2009

### Cyosis

You know that $a \log b=\log b^a$ and you also know that $\log a+\log b=\log ab$. Try to apply these to your expression, to find the correct results (both the results you listed are incorrect).

Last edited: Jun 11, 2009
3. Jun 11, 2009

### Fairy111

So it would be log(b^a . d^c) ?

4. Jun 11, 2009

### tiny-tim

Hi Fairy111!

(try using the X2 tag just above the Reply box )
Yup!