Chapter 8, Sequences and Series - Section 8.1 - Sequences and Summation Notation - 8.1 Exercises - Page 600: 10

$a_1=1$ $a_2=\frac{1}{4}$ $a_3=\frac{1}{9}$ $a_4=\frac{1}{16}$ $a_{100}=\frac{1}{10000}$

We are given: $a_{n}= \frac{1}{n^{2}}$ We evaluate: $a_1= \frac{1}{(1)^{2}}=1$ $a_2= \frac{1}{(2)^{2}}=\frac{1}{4}$ $a_3= \frac{1}{(3)^{2}}=\frac{1}{9}$ $a_4= \frac{1}{(4)^{2}}=\frac{1}{16}$ $a_{100}= \frac{1}{(100)^{2}}=\frac{1}{10000}$