Answer
$1,\dfrac{-1}{4},\dfrac{1}{9},\dfrac{-1}{16}, \dfrac{1}{32}$
Work Step by Step
Need to find the first five terms of $a_n=\dfrac{(-1)^{n+1}}{n^2}$ when $n=1,2,3,4,5$
Thus,
$a_1=\dfrac{(-1)^{1+1}}{1^2}=1$
$a_2=\dfrac{(-1)^{2+1}}{2^2}=\dfrac{-1}{4}$
$a_3=\dfrac{(-1)^{3+1}}{3^2}=\dfrac{1}{9}$
$a_4=\dfrac{(-1)^{4+1}}{4^2}=\dfrac{-1}{16}$
$a_5=\dfrac{(-1)^{5+1}}{1^5}=\dfrac{1}{32}$
Hence, the first four terms are: $1,\dfrac{-1}{4},\dfrac{1}{9},\dfrac{-1}{16}, \dfrac{1}{32}$
