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

Jan 8, 2018

$- 1 , 2 , \frac{2}{3} , - \frac{3}{4} , \frac{4}{5} , - \frac{5}{6}$

#### Explanation:

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

Let $n = 1 : {\left(- 1\right)}^{1} \left(\frac{1}{1 + 1}\right) = - \frac{1}{2}$

Let $n = 2 : {\left(- 1\right)}^{2} \left(\frac{2}{2 + 1}\right) = \frac{2}{3}$

Let $n = 3 : {\left(- 1\right)}^{3} \left(\frac{3}{3 + 1}\right) = - \frac{3}{4}$

Let $n = 4 : {\left(- 1\right)}^{4} \left(\frac{4}{4 + 1}\right) = \frac{4}{5}$

Let $n = 5 : {\left(- 1\right)}^{5} \left(\frac{5}{5 + 1}\right) = - \frac{5}{6}$