Solution 2.9.4.4 F(s)= A s + B (s +4) 2 + C s +4 : A = [[sF(s)]] s=0 =  5(s +1) (s+4) 2  s=0 = 5 16 B = h [(s +4) 2 F(s)] i s=;4 =  5(s +1) s  s=;4 =3 C =  d ds [(s +4) 2 F(s)]  s=;4 =  d ds 5(s +1) s  s=;4 =  ;5(s +1) s 2 + 5 s  s=;4 = ;0:3125 f(t)=[0:3125+ 3:75te ;4t ;0:3125e ;4t ]1(t): 1