#### Question

If n \in N^+ , prove

\dfrac{1}{2}\leq\dfrac{1}{n+1}+\dfrac{1}{n+2}+\dots+\dfrac{1}{2n}<1

Question

If n \in N^+ , prove

\dfrac{1}{2}\leq\dfrac{1}{n+1}+\dfrac{1}{n+2}+\dots+\dfrac{1}{2n}<1

\because n < n+k <2n

\therefore \dfrac{1}{2n} <\dfrac{1}{n+k}<\dfrac{1}{n}