# Homework Help: Logarithm notation question

1. Jul 19, 2012

### Feodalherren

1. The problem statement, all variables and given/known data
$\left(ln\stackrel{2}{}(1+x)=4\right)$

I've never seen a number above the ln like that, usually it's on another term or simply ln(2). What does that numer mean? Is it Log(e)^2 i.e. (Loge)(Loge)? That doesn't make any sense to me.
2. Relevant equations
-

3. The attempt at a solution

Bring the 2 down and divide both sides by it.
ln (1+x)=2

(e^2) - 1=x

It's supposed to have one more solution, x = (1/(e^2)) - 1

2. Jul 19, 2012

### micromass

It means

$(ln(1+x))^2=4$

3. Jul 19, 2012

### Feodalherren

Ah that makes complete sense. Thank you.

4. Jul 20, 2012

### HallsofIvy

Remember that for, any function, f, the notation "f(x)" means the function evaluated at x- that is, f(x) is a number and so $f^n(x)$ is that number to the nth power. Generally, for any function, f, the notation fn means "the value of f to the nth power".

The only (unfortunate) exception to that is '-1'. $f^{-1}$ typically means "the inverse function", not 1/f.