# How do you write the first five terms of the sequence a_n=(1+(-1)^n)/n?

Mar 8, 2017

The first five terms of the sequence are $\left\{0 , 1 , 0 , \frac{1}{2} , 0\right\}$

#### Explanation:

To find the first five terms of the sequence ${a}_{n} = \frac{1 + {\left(- 1\right)}^{n}}{n}$, put integer values of $n$ from $1$ to $5$ and we get

${a}_{1} = \frac{1 + {\left(- 1\right)}^{1}}{1} = 0$

${a}_{2} = \frac{1 + {\left(- 1\right)}^{2}}{2} = 1$

${a}_{3} = \frac{1 + {\left(- 1\right)}^{3}}{3} = 0$

${a}_{4} = \frac{1 + {\left(- 1\right)}^{4}}{4} = \frac{1}{2}$

${a}_{5} = \frac{1 + {\left(- 1\right)}^{5}}{5} = 0$

Hence, the first five terms are $\left\{0 , 1 , 0 , \frac{1}{2} , 0\right\}$