1. The problem statement, all variables and given/known data Hello everyone, I have a problem to solve, which I found hard and so looked for help on the web. Finally found this: https://books.google.co.uk/books?id...E#v=onepage&q=clausius-duhem inviscid&f=false which is great as on page 183 is the EXACT question I am supposed to solve. It's not fully shown on google but I can do the rest. There a a few differences: I have T=T(F,Θ,gradΘ) q=q(F,Θ,gradΘ) η=η(F,Θ,gradΘ) rather than T=T(ρ,Θ,gradΘ) etc. as in the link above. The Clausius-Duhem inequality shown throughout the book has terms a term +T⋅D in it. We learned this differently in class: Our inequality read the exact same as in the link above but had a term +tr(TD) instead. I would really like to understand why these two forms are equivalent before just using the form I found on the web and assuming it's correct. Is this to do with T vs. T? I feel like such a beginner (which I am!) :D Thank you so much for any advice!!