For a given function, for example
f(x) = x * y I know the uncertainties of the variables
y. For the sake of this question, we can assume
x +/- 0.1 and
y +/- 0.3.
I want to calculate the uncertainty of
I have seen that the formula to calculate the error propagation of a multiplication operation uses the relative error of the variables, as it is shown in the following image:
The problem is the value of the variable
x belongs to an interval
[0 - 255] and
y is a fixed value. The relative error of
y it is easy to calculate but I do not know the approach to calculate the relative error of the variable
x to be used in the formula.
Is there a way to calculate the uncertainty of
f() without the relative error of
x? Can I only use the uncertainties like in the addition formulas of the error propagation?
I have never worked with this kind of analysis, all that I know was self taught, so any detail given to me will be very appreciated.