Removing the extra " ) " at the end of that line, yields plots and no errors.
%Part a)
R=287; % Specific gas constant in J/kg.k
M=[2:0.1:6];
gamma=1.4;
P_0_1=101325; % Pressure at sea level in Pa unit
for n=1:length(M);
P_0(n,1)=((1+((gamma-1))/2).*M(n).^2).^(gamma/(gamma-1)).*P_0_1;
end
P_0_ratio=P_0./P_0_1;
figure (1)
plot (M, P_0_ratio)
xlabel('Moch Number')
ylabel('Total stagnation pressure ratio P_0/P_0_1')
title('Total stagnation pressure ratio P_0/P_0_1 vs. Moch Number')
%Part b)
for n=1:length(M);
delta_s_r(n,1)=-log(P_0_ratio(n));
end
figure(2)
plot (M,delta_s_r)
xlabel('Moch Number')
ylabel('Dimensionless entropy change \delta s')
title('Dimensionless entropy change \delta s vs. Moch Number')
