# Log Rules

1. May 1, 2014

### SteveDC

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

Got to part of a problem where I have exp(-3ln(x)) and I am confused as to whether the next step is:

a) exp(ln(x^-3)) = x^-3

or

b) exp(-ln(x^3)) = -x^3

I think the correct step is (a) but not certain, any help would be great :)

2. May 1, 2014

### SammyS

Staff Emeritus
Yes (a) is the correct result.

For (b):

exp(-ln(x^3)) = $\displaystyle \frac{1}{e^{\ln (x^3)}}\$ → $\displaystyle \ \frac{1}{x^3} \ .$

3. May 2, 2014

### vela

Staff Emeritus
Here it appears you're saying $e^{-a} = -e^a$, that you can simply pull the minus sign out front, which you probably know isn't correct.