Matlab (1) - Vykreslení LTIL soustavy

syms ya yb y
ya=dsolve('2*Dya+ya=0','ya(0)=-1');
yb=dsolve('2*Dyb+yb=1','yb(0)=0');
yy=ya+yb;
y=dsolve('2*Dy+y=1','y(0)=-1');

figure(1);
subplot(3,1,1);
ezplot(ya,[0 10]);
xlabel('ya(t)');

subplot(3,1,2);
ezplot(yb,[0 10]);
xlabel('ya(t)');

subplot(3,1,3);
ezplot(yy,[0 10]);
xlabel('ya(t)');