Find the general term of the sequence LaTeX: \displaystyle -2,-1,- \frac{1}{2},\ldots

The common ratio is LaTeX: \displaystyle r=\frac{a_2}{a_1}=\frac{1}{2} . Using the first term and the common ratio gives LaTeX: \displaystyle a_n=-2\left( \frac{1}{2} \right)^{n-1}