Question

Să se arate că:
1/1+1/√2+1/√3+...+1/√n> sau egal cu √n , n aparține N*
Va rog, e urgent!!!!
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Answer 1

$\it \dfrac{1}{1}+\dfrac{1}{\sqrt2}+\dfrac{1}{\sqrt3}+\ ...\ +\dfrac{1}{\sqrt n} \geq \underbrace{\dfrac{1}{\sqrt n}+\dfrac{1}{\sqrt n}+\dfrac{1}{\sqrt n}+\ ...\ +\dfrac{1}{\sqrt n}}_{n\ termeni}=\dfrac{n}{\sqrt n}=\\ \\ \\ =\dfrac{\sqrt n\cdot\sqrt n}{\sqrt n}=\sqrt n$