This is LaTeX code:
[latex]
\frac{1}{n + 1} \geq \frac{1}{2} \Rightarrow - \frac{1}{n +1} \geq - \frac{1}{2} \Rightarrow 1 - \frac{1}{n +1} \geq \frac{1}{2} n=1
[/latex]