13-6

13-6 is all about sigma. A sigma is a series written in condensed form. The sigma is representing with F because I’m too lazy to make it.

The Sigma contains three parts. The summand is the limits of summation, and the index. The number to the right of the Sigma is the summand. The number on top of the Sigma is the limits of summation. The number on the bottom of the Sigma is the index. You can either be asked to expand the Sigma or evaluate the sigma. To expand you only plug the numbers was they need to go. To evaluate you solve the whole thing.


The greek letter sigma is often used in mathematics to express a series or its sum in abbreviated form.

6
F4k
K = 2

Find the Summand? 4k
What is the index? k
What are the limits of summation? 5 and 2

Evaluate the Sigma

4(2) + 4(3) + 4(4) + 4(5) + 4(6)
8 + 12 + 16+ 20 + 24 = 80

Basically 13-6 is easy but it can mess you over if you don't know all the information about stigma if you do you will easily breeze threw this section.