# Math Project: Modelling Functions

• Mar 1st 2010, 04:49 AM
positiveion
Math Project: Modelling Functions
The image is fairly large so here is the URL to the assignment that I scanned:
http://img9.imageshack.us/img9/4811/img065h.jpg

These are the points plotted:
http://i83.photobucket.com/albums/j283/ta_lia/01-7.jpg

The are the points plotted with a linear function which I THINK is an accurate fit:
http://i83.photobucket.com/albums/j283/ta_lia/02-3.jpg

What I am having serious trouble with is the function and how to estimate/interpret the function. I have not encountered anything like this before and I am very confused.

• Mar 1st 2010, 06:10 AM
HallsofIvy
You mean you just want to find the equation of the line?

Theoretically a line is determined by two points. Any (non-vertical) line can be written in the form y= ax+ b. Take two points and put their x, y values into that to get two equations for a and b. Since both will have "+b", subracting one equation from the other will immediately eliminate b and give you a single equation to solve for a. Put that value of a back into either equation and solve for b.

Practically, since those points are NOT on a perfect line, different choices of the two points will give different equations. You can get the most accurate line by using the two points at opposite ends.
• Mar 1st 2010, 08:02 AM
positiveion
No. I know how to find the equation of the line. What I do not understand is what to do next when following my worksheet.

The don't understand the function P(t)=K/1+Le^-Mr, how to use it or how to find it.

EDIT: that was too big. Please click the following link for URL to question sheet: http://img9.imageshack.us/img9/4811/img065h.jpg