Question

Express each sum in sigma-notation

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

Answer 1

9514 1404 393

Answer:

  $\displaystyle\sum\limits_{n=1}^{20}{\dfrac{1}{n^2}}$

Step-by-step 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 ...

  $\displaystyle\sum\limits_{n=1}^{20}{\dfrac{1}{n^2}}$