Algebra Examples

$a_{n} = \frac{{(- 1)}^{n}}{n^{2}}$

Step 1

Substitute in the value of $n$ to find the $n$ th term.

$a_{3} = \frac{{(- 1)}^{3}}{{(3)}^{2}}$

Step 2

Raise $- 1$ to the power of $3$ .

$a_{3} = \frac{- 1}{3^{2}}$

Step 3

Raise $3$ to the power of $2$ .

$a_{3} = \frac{- 1}{9}$

Step 4

Move the negative in front of the fraction.

$a_{3} = - \frac{1}{9}$