%求卷積和拉普拉斯變換
syms t s tao;
syms a  positive		%對常數進行“限定性”設置				 	 
pause,y2=sym('Dirac(t-a)+Dirac(t+a)')%<2>
ezplot(y2,[-5,5])
pause,y1=sym('exp(-2*t)*Heaviside(t-1)')
ezplot(y1,[-2,2])
pause,y3=sym('t*(Heaviside(t)-Heaviside(t-1))+exp(-t)*Heaviside(t-1)')
ezplot(y3,[-2,2]);
pause,Mt=[y2 y1 y3];
laplace(y2,t,s)
laplace(y1,t,s)
pause,MS=laplace(Mt,t,s) ,ms=simple(MS)

yt=int(subs(y1,t,tao)*subs(y2,t,t-tao),tao,0,t)