Hi everyone! 1. The problem statement, all variables and given/known data Just one part of the lecture notes I couldn't work out how to derrive (apparently we need to know how). A/A*=1/M[2/(k+1)(1+(k-1)/2*M^2)]^(k+1/2(k-1)) 2. Relevant equations A/A*=1/M[2/(k+1)(1+(k-1)/2*M^2)]^(k+1/2(k-1)) ρ0/ρ=[1+(k-1/2)*M^2]^(1/k-1) To/T=1+(k-2/2)*M^2 Po/P=[1+(k-2/2)*M^2]^(k/k-1) ρ*A*v*=ρAv M=V/C (mach number) c=√(KRT) 3. The attempt at a solution I tried fiddling around with quite a few things but got nothing. Thanks!