求下列函数的卷积积分f1(t)*f2(t): (1)f1(t)=tε(t),f2(t)=ε(t); (3)f1(t)=f2(t)=e-2tε(t);
求下列函数的卷积积分f1(t)*f2(t): (1)f1(t)=tε(t),f2(t)=ε(t); (3)f1(t)=f2(t)=e-2tε(t); (5)f1(t)=tε(t),f2(t)=e-2tε(t); (7)f1(t)=ε(t)一ε(t一4),f2(t)=sin(πt)ε(t); (9)f1(t)=tε(t一1),f2(t)=ε(t+3);