Talk:Introduction to generating functions

Formal sense

What does this mean when we say "formal sense"? Does it mean I can put those coefficients to be anything without worrying whether or not the function actually converges? --HappyCamper 19:47, 9 March 2007 (UTC)

"Formal" here means "in virtue of the form." So, it's the "form" of the power series that we're using. It's a nice, concise way to express a sequence.

In practice, we don't care at all whether these series converge. There will be times where we have to consider radii of convergence, but in the introduction, I wanted to just talk about basically what these things are. –King Bee ^{(τ • γ)} 19:51, 9 March 2007 (UTC)

I guess to really answer your question, the answer is a plain yes. =) –King Bee ^{(τ • γ)} 19:58, 9 March 2007 (UTC)

Okay I see, thank you. I started reading that book you recommended. Very nice :-) --HappyCamper 02:06, 10 March 2007 (UTC)

First tutorial question?

Alright, so I have finally constructed a series which is of interest to me...Let's say we have a sequence that satisfies

$c_{k+2}=-{{c_{k}} \over 2}{\sqrt {\frac {k+1}{k+2}}}$

and say, $c_{0}$ and $c_{1}$ are some fixed constants a and b. Let's also take $k\geq 0$. What's the generating function for this sequence of numbers? I was thinking we can walk through something like this, and put it on a page somewhere. --HappyCamper 04:54, 17 March 2007 (UTC)

So just what IS a power series?

If I am looking at an expression, how can I determine whether it is, or is not, a power series? Is a power series always defined by a summation? Is it required that a power series be a sum over an infinity? Must the only variables involved be the summation one and x? Can the series be a summation over more than 1 variable or with an expression involving more than 1 variable? (29 September 2015‎ by 76.89.22.244)

You might try asking this question at Wikiversity:Help Desk. -- Dave Braunschweig (discuss • contribs) 13:32, 3 October 2015 (UTC)