1. ## parametric equations

I need help with parametric equations....i can't seem to figure out where to start when looking at a problem. The problems i will have to solve include looked at a diagram and figuring out the parametric equations for the trace of a movie point. Any suggestions?

2. Originally Posted by sarah s
I need help with parametric equations....i can't seem to figure out where to start when looking at a problem. The problems i will have to solve include looked at a diagram and figuring out the parametric equations for the trace of a movie point. Any suggestions?
Give a problem that you are unable to do.

3. Originally Posted by sarah s
I need help with parametric equations....i can't seem to figure out where to start when looking at a problem. The problems i will have to solve include looked at a diagram and figuring out the parametric equations for the trace of a movie point. Any suggestions?
If I am understanding what you have to do correctly the I would suggest the following scheme:

Set the lower left corner of the screen as (0, 0). Then you can think of your trace as a series of coordinate points. Pick a starting point for your trace and call this t = 0. Call the coordinates of that point $\displaystyle (x(0), y(0))$.

Now pick a small distance along the path, small enough that the path is (roughly) a straight line over that distance. Record the coordinates of that point as $\displaystyle (x(1), y(1))$.

Using the same distance, find the coordinates of the next point, $\displaystyle (x(2), y(2))$. etc.

So you will have a list of coordinate points at "equal spacings" along the trace.

Now find a best fit function for the x - coordinates, and a separate best fit function for the y - coordinates. This will be your parametric representation of the trace.

-Dan