Sums with sigman notation

What is a sum? It is the combination of all terms added together. The easiest way to complete this is by sigmun notation. Although it is the easiest way there is some calrification that is needed such as what are the upper and lower limits. 

Now that we know what the signs are, how do we do this? You start with the first term or A1. the 1 is the variable n so you would plug it in to the formula. The n at the top is the upper limit. DO NOT PASS IT. 

lastly there are a few rules that must be applied.