function [] = prob_3_4()
% 
% Written by:
% -- 
% John L. Weatherwax                2006-10-16
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

close all; 

% Assign a speed of sound c_0:
% 
c_0 = 1;

% Assign the x-domain: 
% 
xs = linspace( -2, 4 ); 

t1 = abs((1-xs)/c_0); 
t2 = abs((2-xs)/c_0); 

% the intersection of the two: 
tstar = 1/(2*c_0); xstar = 3/2; 

figure; hold on; 
plot( xs, t1, '-o' ); 
plot( xs, t2, '-rx' ); 
text( xstar+0.15, tstar, '(x^*,t^*)' ); 
xlabel( 'x' ); ylabel( 't' ); %grid on; 
saveas( gcf, '../LeVeque_WU_FVM/Graphics/prob_3_4.eps', 'psc2' );