# How to deal with the summation?

• Mar 24th 2011, 12:28 AM
oxxiissiixxo
How to deal with the summation?
Attachment 21241
See Attachment. I do not know how to expand the equation stated in the attachment. The "!" is very confusing me. I tried to expand the equation on my own and input values into it, but I can't get the correct value so I guess that I may do something wrong.
Can someone help me to expand that equation for me once? Thank you.
• Mar 24th 2011, 04:13 AM
Prove It
$\displaystyle !$ is the factorial symbol. Basically, if $\displaystyle n$ is a positive integer, then $\displaystyle n! = n \cdot (n-1) \cdot (n-2) \dots 3 \cdot 2 \cdot 1$