# Math Help - How to find this limit?

1. ## How to find this limit?

lim((n-1)/n)^n,n->+inf)
calculator gives me e^-1 bt I don't know how.

2. Originally Posted by ninano1205
lim((n-1)/n)^n,n->+inf)
calculator gives me e^-1 bt I don't know how.
Notice that $\tfrac{n-1}{n} = 1 - \tfrac{1}{n}$.

You should know that $\left( 1 + \tfrac{1}{n} \right)^n \to e$, in general $\left( 1+\tfrac{k}{n} \right)^n \to e^k$.
Therefore, $\left( 1 - \tfrac{1}{n} \right)^n \to e^{-1}$.

3. ## calculus

Which part of calculus should I study if I don't know this?
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