clc syms t s=%s; //Factorizing the denominator I=(s-10)/((s^2)*(s-%i)*(s+%i)); disp(I,"I(s)=") //The principal part at s=0 is //B1/s+B2/s^2 //Taking the limit s->0 to (s-10)/((s-%i)*(s+%i)) B2=-10 //Taking the limit s->0 to (s*(s-10))/(s^2)*(s^2+1)+(10/s) B1=1 //The principal part at s=%i is //A/(s-%i) //Taking the limit s->%i to (s-10)/((s^2)*(s+%i)) A=(-0.5-%i*5) //As the other co-efficient is conjugate of the above we can write the partial fraction expansion of I(s) I=(1/s)-(10/s^2)-(0.5+%i*5)/(s-%i)-(0.5-%i*5)/(s+%i); //Taking inverse of each term I1=ilaplace('1/s',s,t) I2=ilaplace('10/s^2',s,t) I3=ilaplace('(0.5+%i*5)/(s-%i)',s,t) I4=ilaplace('(0.5-%i*5)/(s+%i)',s,t) I=I1-I2-I3-I4 disp(I,"i(t)=")