% Example 12-2: The gas equation

% Initialize the variables
global P T n a b R
R = 0.08206;
P = 6; T = 50 + 273.15; n = 2; a = 3.59; b = 0.047;


% Estimate the V using the ideal gas equation
Vest = n*R*T/P;

% Solve the van der Waals equation
V = fzero(@Waals, Vest)