Answer
$\frac{1}{200}$
Work Step by Step
To calculate $a_n$, we plug in $n$ to the general formula.
To calculate the result, we use PEMDAS (parentheses, exponentation, multiplication, division, addition, subtraction) to determine which operation is applied first.
$a_{100} = \frac{(-1)^{100}}{2(100)} = \frac{1}{2(100)} = \frac{1}{200}$
