OK.

 

so for my lab i needed to take the partial derivative of the following equation with respect to D and y.

 

lambda=(d*(D/y))/m

 

lambda is the wavelength

d is the distance between the slits

D is the distance from the laser to the board

y is the distance from the center maxima to the maxima (m=-4 to 4)

and m an interger multiple of the wavelength of light ( we used -4, -3, -2, -1, 1, 2, 3, 4)

 

I got these equations:

 

dlambda/dD= (d/m)*y deltaD

and

dlambda/dy= (d/m)*D delta y

 

You add these together and plug in variables and error to get experimental error. I understand that d, y and D are the values we used in the experiment. I also understand that delta D and delta y are the possible errors in the equipment we used to measure them. the only thing I dont understand when plugging these in is what to use for m?

-Or- have i done something wrong here?

 

Thanks

 

I guess i forgot to mention that for every m we measured y.

m represents the maxima, right? The first maxima on one side is m=1, the next maxima m=2, and so on. So if you want the experimental error of lambda at the first maxima, you use m=1. If you want the experimental error at the second maxima, you use m=2. And so on.