# Proving an inequality involving exponentiation

1. Jul 10, 2010

### hypatia0

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

Show that $$\left( 1 - \frac{\ln n}{kn} \right)^n > \frac{1}{n^{1/k} + 1}$$ holds for all integers $$n\geq 1$$ and $$k\geq 2$$.

3. The attempt at a solution

I first tried to find a proof for $$k=2$$ by showing that the quotient LHS/RHS goes to 1 and has negative slope everywhere, but this becomes rather unwieldy.

2. Jul 10, 2010

### hunt_mat

I would be tempted to try a proof by induction on n. Show that the inequality holds for n=1, Assume there is an integer m for which the inequality holds and show it's true for m+1.

Mat