For ervery loop, you have only one point (x,y) which you can not plot as a line. Use plot(x, y, 'bo') to plot the point instead. If you want to join the dots, you need to store the (x,y) values over the loop.
syms theta v omega omega1
mu1 = mu0*(((T+459.67)/T0)^(1.5)) * ((T0+s)/((T+459.67)+s));
fprintf("More collisions in a gas means more momentum transfer making the gas more viscous.",mu1);