00:03
Okay, here we have an expanded series, and we are tasked with writing it in summation notation using sigma and all that stuff.
00:16
And the easiest way to do these is first identify where your variable is going to be.
00:22
And of course, a variable comes from the word vary, which means to change.
00:26
And so you want to look for the term in each of these, or i should say you want to look for.
00:33
For the part of each of these terms that's changing.
00:36
That's going to tell you where your variable goes.
00:42
So we can start with n equals 1, and then you can see n equals 2, 3, all the way to 15.
00:52
So what that tells us is our sigma is going to have 1 on the bottom and 15 on the top.
01:06
And this one's easy enough to do because notice that's the only thing...