Focal length of a concave mirror

[hds29ka]

Homework Statement

Focal length of a concave mirror.
This was an experiment, done in class.

I was required to collect a light globe:(of course with a power source) for the object, paper:screen/image, and a concave mirror.

I created the images, of the globe filament, to the screen, and measured.

I took 5 trials of V and U, where; U=Object distance, and V= Image distance. The results were; 1.)V=25.0, U=38.0
2.)V=22,0, U=47.0
3.)V=20.0, U=57.5
4.)V=18.5, U=75.0
5.)V=18.0, U=88.5

From here, I could use the graphics calculator (1/v for y-axis, and 1/u for x-axis), or 1/f=1/v+1/u for each and average them.

Question 1.: What is the graphical method (calculator.)?
Question 2.: What is the Mirror equn method?
Question 3.: Why is the graphical method more accurate, than 1/f=1/v+1/u?

Homework Equations

1/f=1/v+1/u

The Attempt at a Solution

1.) stat, 1/u for list1, 1/v for list2, GRPH, GPH1, X, Copy, Menu, GRAPH,
Y=-1.0522075X+0.067, Enter, G solv, Xcal- when Y=0, Ycal- when X=0.

Then f=1/yintercept and f=1/xintercept for focal length.

2.) average values (of 1/f=1/v+1/u).

 

[kuruman]

What conclusions did you draw? Is there a particular question you wish to ask?

What do you mean when you say

Then f=1/yintercept and f=1/xintercept for focal length.

??