Essentially I'm asking if the uncertainty in μ = -5 log10 (d/10) is given by Δμ = 5 * ( Δd / d*ln(10) ) 1. The problem, all variables and given/known data I am to calculate the uncertainty in absolute magnitude (M), which is calculated using an equation involving logs. The equation for M is: M = m - 5 log10 (d/10) where m and d have associated errors Δm and Δd. 3. The attempt at a solution I introduce: μ = -5 log10 (d/10) such that M = m + μ Then I calculate the error in μ whereby: Δμ = 5 * ( Δd / d*ln(10) ) I then calculate the error in M by: ΔM2 = [ Δm2 + Δμ2 ] Any comments on this would be greatly appreciated as I have 0 confidence in myself when it comes to calculating errors.