Could someone explain to me the use of errors bars in the X-axis?

[Intuition]

Hello!

 

I am working currently working on my extended essay in physics.

There's one thing I am a little bit unsure of, and that is the use of error bars in the x-axis.

 

Okay, so by having them in the y-axis, you can make max-min slope lines, which is great. 

 

So I am thinking, and I could think of these solutions:

1. Just put them in, then you have error bars in both the x-axis and the y-axis, then graph the max/min slope lines from wherever that the slopes are at their maximum/minimum - The max/min slopes would then look like this:

 

Very bad sketch. Anyways, the maximum slope would go from the minimum y-value, but maximum x-value of point 1 to maximum y-value and minimum x-value of point 2. Opposite for minimum slope. This makes their gradient as high/low as possible within the bars.

 

2. Calculate how much difference the uncertainty in the x-values (using the gradient from the trend line) the uncertainty in the x-axis could possible make on the respective y-value plotted and then add this uncertainty to the error bars in the y-axis instead.

 

3. Dont know 

[Intuition]

Okay, I found it!

Listed in this document.

http://mrsmithsphysics.weebly.com/uploads/1/2/1/5/12150755/1.2_errors_and_uncertainties_notes.pdf

 

Apparently, one is suppsoed to do what I wrote in [1] - make the error bars from "corner to corner" of the error boxes.