S_{n}=\frac{gn^2}{2}\\
\Delta S=S_{n}-S_{n-1}=\frac{gn^2}{2}-\frac{g(n-1)^2}{2}=\bold{\frac{g(2n-1)}{2}}" alt="S=\frac{gt^2}{2}, t=n|=>S_{n}=\frac{gn^2}{2}\\
\Delta S=S_{n}-S_{n-1}=\frac{gn^2}{2}-\frac{g(n-1)^2}{2}=\bold{\frac{g(2n-1)}{2}}" align="absmiddle" class="latex-formula">