Question

is there any shortcuts for sigma notations ?

Answer 1

http://www.saskschools.ca/curr_content/mathb30/seq_series/les3/notes.htm

Answer 2

Σ sum of terms

@sunshine0719 --> Do you mean shortcuts to get the sigma symbol?

Answer 3

noo\[\sum_{n=1}^{82} 2(n-1)\]

Answer 4

likee for tht example the top number is a large number
isn't there a shortcut instead of adding all of them up, all the way to 82

Answer 5

yes, there are formulas to be utilised here

Answer 6

first off you can simplify this\[\sum_{i=1}^{n}2(i-1)=-2n+2\sum_{i=1}^{n}i\]

Answer 7

second, you can use the formula\[\sum_{i=1}^{n}i={n(n+1)\over2}\]and just plug in whatever your particular \(n\) happens to be
in your case \(n=82\)

Answer 8

of course, if sigma notation is all new to you you probably have no idea how I did that stuff up there...
start with thinking about general forms...

challenge: see if you can figure out what\[\sum_{i=1}^{n}1\]is