basic animation questions

Hi all,
I have a path on which I want my object to move. I have generated the path using splines. I have all the points that are used to generate the path in a variable say point[count].
I have the following questions:

  1. If i want to calculate the tangent at any point how do i do it?
    2)How do i calculate the velocity and acceleration at any given point??

can you point me to any resources on the web the above information. Any sort of information will be appreciated.
Thanx
-prasad-

  1. To find the tangent of a piecewise smooth curve that defines a path, the tangent of the path at any point on the path, x, but not on a point in the set that defines the path, is simply the unit vector parallel to the line segment from point p1 to p2 and x is on that line segment. If x=p1 or x=p2, then it is customary to use the average tanget of the two segments the point straddles. Note: If the spline can be defined by a continuous parameterization [b]s/b, then the tangent [b]T/b=s’(t)/|s’(t)|.

  2. Assuming count is a function of time, then the velocity is just the first time derivative and the acceleration is just the first time derivative of the velocity.

[This message has been edited by DFrey (edited 11-19-2000).]