Question

Express each sum in sigma-notation

1 + 1/4 + 1/9 + 1/16 + ... + 1/400

Answer 1

9514 1404 393

Answer:

`\displaystyle\sum\limits_(n=1)^(20){(1)/(n^2)}`

Explanation:

We notice that the denominator of each term is the square of the term number, so the last term must be the 20th. The sum is then ...

`\displaystyle\sum\limits_(n=1)^(20){(1)/(n^2)}`