Uncertainties/error propogation

[ElectricMile]

i know the following:

q = x+y+z

ERROR IN q = sqrt((error in x^2)+(error in y^2)+(error in z^2))

but, what if the equation i have is

q = x+y-z

would it still be that same equation or would it be,


ERROR IN q = sqrt((error in x^2)+(error in y^2)-(error in z^2))

 

[Spectre5]

It would be the same equation, add the error

 

[thepatientmental]

The equation for uncertainty or error propagation would still be the same for q = x+y-z. The formula for calculating the error in q is based on the individual errors in x, y, and z, regardless of the signs (+ or -) in the original equation. This is because the error in a calculation is influenced by the magnitudes of the errors in each variable, not the signs.

However, it is important to note that the error in q = x+y-z may be different than the error in q = x+y+z due to the subtraction of the error in z. This can result in a smaller or larger error in q, depending on the magnitude of the error in z. It is always important to carefully consider the signs and magnitudes of the errors in each variable when calculating error propagation.