Question

Which of these is the denominator while finding the root mean square residual?

(a) Sum of the absolute residuals

(b) Sum of the actual residuals

(c) Number of elements

(d) Sum of the scaled residuals

This question was addressed to me in quiz.

My question comes from Relaxation in section Discretization of the Source Term & Relaxation of Computational Fluid Dynamics

Answer 1

Right answer is (c) Number of elements

The best I can explain: The root mean square is the ratio of the square root of the sum of squares of the absolute residuals to the number of residuals. The number of residuals is the same as the number of elements.