# Homework Help: How to find the f(x) (least square method)

1. Dec 6, 2011

### mjmara

Hi my first post , I hope I chose the right forum?

I'm here looking for a memory jog not for someone to do my work, I'm trying to remember how to find the f(x) to complete this chart , there is many more data points but I'm just providing you with the top line , I shall do the rest myself, can someone help me please?
It's been many years since I attempted this problem :(

x y x^2 xy f(x) f(x)-y (f(x)-y)^2
________________________________________________
-8 6.8 64 -54.4 ?
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Dec 6, 2011

### mjmara

sorry

the format is all messed up

here

x___y___x^2___x.y____f(x)
-8__6.8__64____-54.4__?

sorry for the format but this is the best I can do

x= -8
y= 6.8
x^2 = 64
x.y = -54.4
f(x) = ?

3. Dec 6, 2011

### HallsofIvy

It still is not at all clear what you are asking. Yes, if x= -8 and y= 6.8, then $x^2= 64$ and $xy= -54.4$ but that has nothing to do with some function, "f". Do you have any other information?

4. Dec 7, 2011

### Staff: Mentor

A google search on method of least squares will find some good examples for you to follow, if I have you right. Here is one that may help.