Recent content by basichan

Can u explain more about how to write it as the sum of 3terms involving the expression ##f f' + r##?

I think in the last line you made a mistake, it should be r, not r^2.

Thank you for your explanation, then what kind of lecture, subject or book would teach such techniques?

You are correct, I got it, but how do you know we need to define a function like that to solve it?

I just won't to lead others to my way of solution, maybe there could be another way. So that I haven't post it.

Yes, I actually already have the recursion relation before I post this question, but what I need is the formal algebraic expression.

If there are 4 points on the circle, a, b, c, d in turn for example, we can only connect a with b, and c with d, or a with d, b with c. These is all the possible way we can do.

I would like to say it again, the legal curve or lines are these doesn't go across any of other lines or curves, any any point can only be connected to another unique point.

I am not sure what your mean. I mean any line or curve you can draw is legal, the rules are the lines cannot cross each other, and cannot go beyond the plane of the circle and have to be inside the circle. That's all.

For example, if there are two points on the circle, there is trivially one way to connect the two points. No matter the line is a straight line or a curve.

It means that the only important thing is which two points is connected, the shape of the line of connection doesn't matter.

Homework Statement There are 2n points on a circle, we want to connect each two of them to make a pattern of connection in the way that there is no cross between the lines of connection, and all the lines have to be inside the circle and on the plane of the circle. Question: How many different...