1. The problem statement, all variables and given/known data I conducted an experiment to find the refractive index of several concentrations of sugar solutions. I now need to find out the final uncertainty of my measurements but am unsure of how to go about calculating it. 2. Relevant equations I took 2 measurements of length which i estimate the uncertainty to be +/- 0.025cm (let these measurements of length be a & b) I divided these two lengths and took the arctan of them: c=arctan(a/b) I then placed it in this equation: 2sin(c/2+pi/6) What happens to the uncertainty? 3. The attempt at a solution I am not too sure with the trigonometric operators but I assume they don't do anything to the uncertainties. I am guessing that if this is true, then i just use the usual uncertainty rules of +, -, /, * ? Thanks so much!