initial commit / add all books

32 files changed, 418 insertions, 0 deletions

diff --git a/62/CH7/EX7.11/ex_7_11.sce b/62/CH7/EX7.11/ex_7_11.sce
new file mode 100755
index 000000000..45a102826
--- /dev/null
+++ b/62/CH7/EX7.11/ex_7_11.sce
@@ -0,0 +1,7 @@
+clc;

+clear;

+close;

+z=%s;

+Hz=syslin('d',(z/(2*z^2-3*z+1)));

+ss=tf2ss(Hz)

+disp(ss)

diff --git a/62/CH7/EX7.14/ex_7_14.sce b/62/CH7/EX7.14/ex_7_14.sce
new file mode 100755
index 000000000..aea99c33a
--- /dev/null
+++ b/62/CH7/EX7.14/ex_7_14.sce
@@ -0,0 +1,6 @@
+clc;

+close

+clear;

+s=%s;

+tf=syslin('c',(1/(s^2+3*s+2)));

+ss=tf2ss(tf);

diff --git a/62/CH7/EX7.15/ex_7_15.sce b/62/CH7/EX7.15/ex_7_15.sce
new file mode 100755
index 000000000..690ba639c
--- /dev/null
+++ b/62/CH7/EX7.15/ex_7_15.sce
@@ -0,0 +1,7 @@
+clc;

+close

+clear;

+s=%s;

+tf=syslin('c',((4*s+1)/(s^2+3*s+2)));

+ss=tf2ss(tf);

+disp(ss)
\ No newline at end of file
diff --git a/62/CH7/EX7.16/ex_7_16.sce b/62/CH7/EX7.16/ex_7_16.sce
new file mode 100755
index 000000000..abb2d9f29
--- /dev/null
+++ b/62/CH7/EX7.16/ex_7_16.sce
@@ -0,0 +1,14 @@
+clc;

+close

+clear;

+s=%s;

+b0=1;

+b1=2;

+b2=3;

+b3=4;

+a1=5;

+a2=6;

+a3=7;

+tf=syslin('d',((b0*s^3+b1*s^2+b2*s^1+b3)/(s^3+a1*s^2+a2*s+a3)));

+ss=tf2ss(tf);

+disp(ss)
\ No newline at end of file
diff --git a/62/CH7/EX7.18/ex_7_18.sce b/62/CH7/EX7.18/ex_7_18.sce
new file mode 100755
index 000000000..407e2d75f
--- /dev/null
+++ b/62/CH7/EX7.18/ex_7_18.sce
@@ -0,0 +1,7 @@
+clc;

+close

+clear;

+s=%s;

+tf=syslin('c',((3*s+7)/((s+1)*(s+2)*(s+5))));

+ss=tf2ss(tf);

+disp(ss)
\ No newline at end of file
diff --git a/62/CH7/EX7.20/ex_7_20.sce b/62/CH7/EX7.20/ex_7_20.sce
new file mode 100755
index 000000000..700f3df4e
--- /dev/null
+++ b/62/CH7/EX7.20/ex_7_20.sce
@@ -0,0 +1,8 @@
+clc;

+syms n;

+A=[0 1;-1/8 3/4];

+e=spec(A);

+b1=(e(2)^n-e(1)^n)/(e(2)-e(1));

+b0=e(2)^n-b1*e(2);

+An=b0*eye(A)+b1*A;

+disp(An,"A^n")
\ No newline at end of file
diff --git a/62/CH7/EX7.24/ex_7_24.sce b/62/CH7/EX7.24/ex_7_24.sce
new file mode 100755
index 000000000..3e3da9d60
--- /dev/null
+++ b/62/CH7/EX7.24/ex_7_24.sce
@@ -0,0 +1,8 @@
+clc;

+syms n;

+A=[0 1;-1/3 4/3];

+e=spec(A);

+b1=(e(2)^n-e(1)^n)/(e(2)-e(1));

+b0=e(2)^n-b1*e(2);

+An=b0*eye(A)+b1*A;

+disp(An,"A^n")
\ No newline at end of file
diff --git a/62/CH7/EX7.25/ex_7_25.sce b/62/CH7/EX7.25/ex_7_25.sce
new file mode 100755
index 000000000..f275b1d6f
--- /dev/null
+++ b/62/CH7/EX7.25/ex_7_25.sce
@@ -0,0 +1,8 @@
+clc;

+syms n;

+A=[2 1;0 2];

+e=spec(A);//since we get equal eigen values

+b1=n*e(1)^(n-1);

+b0=e(1)^n-b1*e(1);

+An=b0*eye(A)+b1*A;

+disp(An,"A^n")
\ No newline at end of file
diff --git a/62/CH7/EX7.26/ex_7_26.sce b/62/CH7/EX7.26/ex_7_26.sce
new file mode 100755
index 000000000..fc955eeff
--- /dev/null
+++ b/62/CH7/EX7.26/ex_7_26.sce
@@ -0,0 +1,12 @@
+clear;

+clc;

+close;

+A=[2 1;0 2];

+D=[2 0; 0 2];

+N=[0 1;0 0];

+disp(N^2,"N*N=");

+p=D*N;

+q=N*D;

+if (p==q) then

+    disp("D and N commute")

+end
\ No newline at end of file
diff --git a/62/CH7/EX7.27/ex_7_27.sce b/62/CH7/EX7.27/ex_7_27.sce
new file mode 100755
index 000000000..92878c268
--- /dev/null
+++ b/62/CH7/EX7.27/ex_7_27.sce
@@ -0,0 +1,11 @@
+clc;

+syms n;

+A=[2 0 0;0 -2 1;0 4 1];

+eig=spec(A);

+m=poly(eig(1:2),"A",["roots"]);

+disp(m,"minimal polynomial is")

+e=spec(A);

+b1=(e(2)^n-e(1)^n)/(e(2)-e(1));

+b0=e(2)^n-b1*e(2);

+An=b0*eye(A)+b1*A;

+disp(An,"A^n")
\ No newline at end of file
diff --git a/62/CH7/EX7.29/ex_7_29.sce b/62/CH7/EX7.29/ex_7_29.sce
new file mode 100755
index 000000000..b51392374
--- /dev/null
+++ b/62/CH7/EX7.29/ex_7_29.sce
@@ -0,0 +1,29 @@
+clc;

+A=[0 1;-1/8 3/4];

+B=[0;1];

+C=[-1/8 3/4];

+D=[1];

+Hz=ss2tf(syslin('d',A,B,C,D));

+disp(Hz,"H(z)=");

+z = %z;

+syms n z1; //To f i n d out I n v e r s e z t r a n s f o rm z must be l i n e a r z = z1

+X =z ^2 /((z -(1/2) )*(z -(1/4) ))

+X1 = denom (X);

+zp = roots (X1);

+X1 = z1 ^2 /(( z1 -(1/4) )*(z1 -(1/2) ))

+F1 = X1 *( z1 ^(n -1) )*(z1 -zp (1) );

+F2 = X1 *( z1 ^(n -1) )*(z1 -zp (2) );

+h1 = limit (F1 ,z1 ,zp (1) );

+disp (h1 , ' h1 [ n]= ' )

+h2 = limit (F2 ,z1 ,zp (2) );

+disp (h2 , ' h2 [ n]= ' )

+h = h1+h2;

+disp (h, ' h [ n]= ' )

+n=0:10;

+x=[zeros(1,find(n==0)-1) ones(1,length(n)-find(n==0)+1)];

+hn=2^(1-n)-4^-n;

+y=convol(x,hn);

+plot2d3(n,y(1:length(n)))

+figure

+plot2d3(n,8/3-2^(1-n)+4^-n)

+disp("hence from the figure we can say y[n]=8/3-2^(1-n)+4^-n")

diff --git a/62/CH7/EX7.30/ex_7_30.sce b/62/CH7/EX7.30/ex_7_30.sce
new file mode 100755
index 000000000..9a37de1c1
--- /dev/null
+++ b/62/CH7/EX7.30/ex_7_30.sce
@@ -0,0 +1,22 @@
+clc;

+A=[0 1;-1/8 3/4];

+B=[0;1];

+C=[-1/8 3/4];

+D=[1];

+Hz=ss2tf(syslin('d',A,B,C,D));

+disp(Hz,"H(z)=");

+z = %z;

+syms n z1; //To f i n d out I n v e r s e z t r a n s f o rm z must

+//be l i n e a r z = z1

+X =z ^2 /((z -(1/2) )*(z -(1/4) ))

+X1 = denom (X);

+zp = roots (X1);

+X1 = z1 ^2 /(( z1 -(1/4) )*(z1 -(1/2) ))

+F1 = X1 *( z1 ^(n -1) )*(z1 -zp (1) );

+F2 = X1 *( z1 ^(n -1) )*(z1 -zp (2) );

+h1 = limit (F1 ,z1 ,zp (1) );

+disp (h1 , ' h1 [ n]= ' )

+h2 = limit (F2 ,z1 ,zp (2) );

+disp (h2 , ' h2 [ n]= ' )

+h = h1+h2;

+disp ('for n>=0',h, ' h [ n]= ' )
\ No newline at end of file
diff --git a/62/CH7/EX7.31/ex_7_31.sce b/62/CH7/EX7.31/ex_7_31.sce
new file mode 100755
index 000000000..f05ff43a2
--- /dev/null
+++ b/62/CH7/EX7.31/ex_7_31.sce
@@ -0,0 +1,29 @@
+clc;

+A=[0 1;-1/3 4/3];

+B=[0;1/3];

+C=[-1/3 4/3];

+D=[1/3];

+Hz=ss2tf(syslin('d',A,B,C,D));

+disp(Hz,"H(z)=");

+z = %z;

+syms n z1; 

+X =z ^2 /(1-4*z+3*z^2)

+X1 = denom (X);

+zp = roots (X1);

+X1 = z1 ^2 /((z1-1)*(z1-1/3))

+F1 = X1 *( z1 ^(n -1) )*(z1 -1/3 );

+F2 = X1 *( z1 ^(n -1) )*(z1 -1 );

+h1 = limit (F1 ,z1 ,zp (1) );

+disp (h1 , ' h1 [ n]= ' )

+h2 = limit (F2 ,z1 ,zp (2) );

+disp (h2 , ' h2 [ n]= ' )

+h = h1+h2;

+disp ('for n>=0',h, ' h [ n]= ' ) 

+n=0:10;

+x=2^-n.*[zeros(1,find(n==0)-1) ones(1,length(n)-find(n==0)+1)];

+hn= 3/2-(3^-n)/2;

+y=convol(x,hn);

+plot2d3(n,y(1:length(n)))

+figure

+plot2d3(n,(3/2)-2^-n+(3^-n)/2)

+disp("hence from the figure we can say y[n]=(3/2)-2^-n+(3^-n)/2")  

diff --git a/62/CH7/EX7.32/ex_7_32.sce b/62/CH7/EX7.32/ex_7_32.sce
new file mode 100755
index 000000000..1c0990ede
--- /dev/null
+++ b/62/CH7/EX7.32/ex_7_32.sce
@@ -0,0 +1,8 @@
+clc;

+A=[0 3/2;-1/2 2];

+B=[0.71;-0.71];

+C=[0.71 -0.71];

+D=[0];

+Hz=ss2tf(syslin('d',A,B,C,D));

+disp(Hz,"H(z)=");

+disp(" it has only one pole at z=1/2 and it lies inside the unit circle         hence the system is BIBO stable")
\ No newline at end of file
diff --git a/62/CH7/EX7.35/ex_7_35.sce b/62/CH7/EX7.35/ex_7_35.sce
new file mode 100755
index 000000000..b2362769d
--- /dev/null
+++ b/62/CH7/EX7.35/ex_7_35.sce
@@ -0,0 +1,19 @@
+clc;

+A=[0 1 ;-1/8 3/4];

+B=[0;1];

+C=[-1/8 3/4];

+D=[1];

+Mc=[B A*B];

+if (det(Mc)<>0) then

+    disp("and is controllable",rank(Mc),"Mc has a rank of")

+else

+    disp("and is uncontrollable",rank(Mc),"Mc has a rank of");

+end

+Mo=[C;C*A];

+if (det(Mo)<>0) then

+    disp("and is observable",rank(Mo),"Mo has a rank of")

+else

+    disp("and is unobservable",rank(Mo),"Mo has a rank of");

+end

+Hz=ss2tf(syslin('d',A,B,C,D));

+disp(Hz,"H(z)=");
\ No newline at end of file
diff --git a/62/CH7/EX7.36/ex_7_36.sce b/62/CH7/EX7.36/ex_7_36.sce
new file mode 100755
index 000000000..3ce1967de
--- /dev/null
+++ b/62/CH7/EX7.36/ex_7_36.sce
@@ -0,0 +1,8 @@
+clc;

+A=[0 1;-1/8 3/4];

+B=[0;1];

+q2=[0 ;0];

+q0=[0;1];

+//we know q2=A^2*q0+[B A*B]*X

+X=inv([B A*B])*[q2-A^2*q0];

+disp(X,"therefore [x(1);x(0)]=")
\ No newline at end of file
diff --git a/62/CH7/EX7.37/ex_7_37.sce b/62/CH7/EX7.37/ex_7_37.sce
new file mode 100755
index 000000000..628c1f2fe
--- /dev/null
+++ b/62/CH7/EX7.37/ex_7_37.sce
@@ -0,0 +1,7 @@
+clc;

+c=[-1/8 3/4];

+A=[0 1;-1/8 3/4];

+y=[1;0];

+//we know y=[c;c*A]*q0

+Q0=inv([c;c*A])*y;

+disp(Q0,"therefore [q1(0);q2(0)]=")
\ No newline at end of file
diff --git a/62/CH7/EX7.38/ex_7_38.sce b/62/CH7/EX7.38/ex_7_38.sce
new file mode 100755
index 000000000..b90fcaa30
--- /dev/null
+++ b/62/CH7/EX7.38/ex_7_38.sce
@@ -0,0 +1,17 @@
+clc;

+A=[0 3/2;-1/2 2];

+B=[1;0];

+C=[1 -1];

+D=[0];

+Mc=[B A*B];

+if (det(Mc)<>0) then

+    disp("and is controllable",rank(Mc),"Mc has a rank of")

+else

+    disp("and is uncontrollable",rank(Mc),"Mc has a rank of");

+end

+Mo=[C;C*A];

+if (det(Mo)<>0) then

+    disp("and is observable",rank(Mo),"Mo has a rank of")

+else

+    disp("and is unobservable",rank(Mo),"Mo has a rank of");

+end

diff --git a/62/CH7/EX7.39/ex_7_39.sce b/62/CH7/EX7.39/ex_7_39.sce
new file mode 100755
index 000000000..cd717f231
--- /dev/null
+++ b/62/CH7/EX7.39/ex_7_39.sce
@@ -0,0 +1,9 @@
+clc;

+A=[0 1;-6 -5];

+syms t

+//we know %e^(at)=b0*I+b1*A;

+e=spec(A);//eigen values

+b0=e(1)*%e^(e(2)*t)-e(2)*%e^(e(1)*t);

+b1=%e^(e(1)*t)-%e^(e(2)*t);

+eAt=b0*eye(A)+b1*A;

+disp(eAt,"e^(At)")
\ No newline at end of file
diff --git a/62/CH7/EX7.43/ex_7_43.sce b/62/CH7/EX7.43/ex_7_43.sce
new file mode 100755
index 000000000..8bb92220d
--- /dev/null
+++ b/62/CH7/EX7.43/ex_7_43.sce
@@ -0,0 +1,9 @@
+clc;

+A=[-2 1;1 -2];

+syms t

+//we know %e^(at)=b0*I+b1*A;

+e=spec(A);//eigen values

+b0=e(1)*%e^(e(2)*t)-e(2)*%e^(e(1)*t);

+b1=%e^(e(1)*t)-%e^(e(2)*t);

+eAt=b0*eye(A)+b1*A;

+disp(eAt,"e^(At)")
\ No newline at end of file
diff --git a/62/CH7/EX7.44/ex_7_44.sce b/62/CH7/EX7.44/ex_7_44.sce
new file mode 100755
index 000000000..e42f88c09
--- /dev/null
+++ b/62/CH7/EX7.44/ex_7_44.sce
@@ -0,0 +1,16 @@
+clc;

+syms t

+A=[0 -2 1;0 0 3;0 0 0];

+z=A*A*A;

+if z==0 then

+    disp("A is a nilpotent of index 3");

+else

+    disp("A is not nilpotent")

+end

+//we know %e^(at)=b0*I+b1*A+b2*A^2; 

+e=spec(A);//eigen values

+b2=t^2*%e^(e(3)*t);

+b1=t*%e^(e(2)*t)-b2*2*e(2);

+b0=%e^(e(1)*t)-b1*e(1)-b2*e(1)^2;

+eAt=b0*eye(A)+b1*A+b2*A^2;

+disp(eAt,"e^(At)")
\ No newline at end of file
diff --git a/62/CH7/EX7.45/ex_7_45.sce b/62/CH7/EX7.45/ex_7_45.sce
new file mode 100755
index 000000000..9797afcbd
--- /dev/null
+++ b/62/CH7/EX7.45/ex_7_45.sce
@@ -0,0 +1,10 @@
+clc;

+syms t

+A=[0 -2 1;0 0 3;0 0 0];

+//we know %e^(at)=b0*I+b1*A+b2*A^2; 

+e=spec(A);//eigen values

+b2=t^2*%e^(e(3)*t);

+b1=t*%e^(e(2)*t)-b2*2*e(2);

+b0=%e^(e(1)*t)-b1*e(1)-b2*e(1)^2;

+eAt=b0*eye(A)+b1*A+b2*A^2;

+disp(eAt,"e^(At)")
\ No newline at end of file
diff --git a/62/CH7/EX7.47/ex_7_47.sce b/62/CH7/EX7.47/ex_7_47.sce
new file mode 100755
index 000000000..6aa12c5c0
--- /dev/null
+++ b/62/CH7/EX7.47/ex_7_47.sce
@@ -0,0 +1,31 @@
+clc;

+A=[2 1 0;0 2 1;0 0 2];

+V=[2 0 0;0 2 0; 0 0 2];

+N=[0 1 0;0 0 1;0 0 0];

+z=N*N*N;

+if z==0 then

+    disp("N is a nilpotent of index 3");

+else

+    disp("N is not nilpotent")

+end

+if V*N==N*V then

+    disp("V and N commute")

+else

+    disp("V and N dont commute")

+end

+syms t

+//e^(A*t)=e^(v*t)*e^(N*t)

+e=spec(V);//eigen values

+b2=t^2*%e^(e(3)*t);

+b1=t*%e^(e(2)*t)-b2*2*e(2);

+b0=%e^(e(1)*t)-b1*e(1)-b2*e(1)^2;

+eVt=b0*eye(V)+b1*V+b2*V^2;

+disp(eVt,"e^(Vt)")

+e=spec(N);//eigen values

+b2=t^2*%e^(e(3)*t);

+b1=t*%e^(e(2)*t)-b2*2*e(2);

+b0=%e^(e(1)*t)-b1*e(1)-b2*e(1)^2;

+eNt=b0*eye(N)+b1*N+b2*N^2;

+disp(eNt,"e^(Nt)")

+eAt=eVt*eNt;

+disp(eAt,"e^(A*t)=")
\ No newline at end of file
diff --git a/62/CH7/EX7.48/ex_7_48.sce b/62/CH7/EX7.48/ex_7_48.sce
new file mode 100755
index 000000000..b2a7273f6
--- /dev/null
+++ b/62/CH7/EX7.48/ex_7_48.sce
@@ -0,0 +1,22 @@
+clc;

+A=[0 1;-6 -5];

+b=[0;1];

+c=[1 0];

+q0=[2;1];

+syms t T

+//y=c*e^(A*t)*q0+integ(c*e^A*(t-T)*b*x,0,t) 

+e=spec(A);//eigen values

+b0=e(1)*%e^(e(2)*t)-e(2)*%e^(e(1)*t);

+b1=%e^(e(1)*t)-%e^(e(2)*t);

+eAt=b0*eye(A)+b1*A;

+b0=e(1)*%e^(e(2)*(t-T))-e(2)*%e^(e(1)*(t-T));

+b1=%e^(e(1)*(t-T))-%e^(e(2)*(t-T));

+eAtT=b0*eye(A)+b1*A;

+disp(eAt,"e^(At)");

+ceAtq0=c*eAt*q0;

+ceAtTq0=c*eAtT*q0;

+y=ceAtq0+integ(ceAtTq0*%e^-T,T);

+y0=limit(y,T,0);

+yt=limit(y,T,t);

+Y=yt-y0;

+disp(Y,"y(t)=")
\ No newline at end of file
diff --git a/62/CH7/EX7.49/ex_7_49.sce b/62/CH7/EX7.49/ex_7_49.sce
new file mode 100755
index 000000000..c290815ac
--- /dev/null
+++ b/62/CH7/EX7.49/ex_7_49.sce
@@ -0,0 +1,12 @@
+clc;

+A=[-2 1;1 -2];

+q0=[.5;1];

+//Q=e^(A*t)*q0+integ(e^A*(t-T)*b*x,T,t0,t)

+X=0;

+//therefore integ term is zero

+e=spec(A);//eigen values

+b0=e(1)*%e^(e(2)*t)-e(2)*%e^(e(1)*t);

+b1=%e^(e(1)*t)-%e^(e(2)*t);

+eAt=b0*eye(A)+b1*A;

+Q=eAt*q0;

+disp(Q,"thus [vc1(t)  vc2(t)]=");
\ No newline at end of file
diff --git a/62/CH7/EX7.5/ex_7_5.sce b/62/CH7/EX7.5/ex_7_5.sce
new file mode 100755
index 000000000..7245e70b3
--- /dev/null
+++ b/62/CH7/EX7.5/ex_7_5.sce
@@ -0,0 +1,9 @@
+clc;

+clear;

+close;

+s=%s;

+r=2;

+L=4;

+c=6;

+tf=syslin('c',(1/(L*s+r+(1/(c*s)))));

+ss=tf2ss(tf)

diff --git a/62/CH7/EX7.50/ex_7_50.sce b/62/CH7/EX7.50/ex_7_50.sce
new file mode 100755
index 000000000..c8dd51bcd
--- /dev/null
+++ b/62/CH7/EX7.50/ex_7_50.sce
@@ -0,0 +1,14 @@
+clc;

+A=[0 1;2 1];

+b=[1;-1];

+c=[1 -1];

+d=[0];

+e=spec(A);

+if real(e(1))>0 |real(e(2))>0 then

+    disp("the sytem is not asymptotically stable")

+else

+    disp("the system is asymptotically stable")

+end

+Hs=ss2tf(syslin('c',A,b,c,d));

+disp(Hs,"H(s)=")

+disp("there is only one pole and it is located at -1 which is in the LHP        hence the system is BIBO stable")

diff --git a/62/CH7/EX7.53/ex_7_53.sce b/62/CH7/EX7.53/ex_7_53.sce
new file mode 100755
index 000000000..fd94a9967
--- /dev/null
+++ b/62/CH7/EX7.53/ex_7_53.sce
@@ -0,0 +1,17 @@
+clc;

+A=[0 1;2 1];

+B=[1;-1];

+C=[1 -1];

+D=[0];

+Mc=[B A*B];

+if (det(Mc)<>0) then

+    disp("and is controllable",rank(Mc),"Mc has a rank of")

+else

+    disp("and is not controllable",rank(Mc),"Mc has a rank of");

+end

+Mo=[C;C*A];

+if (det(Mo)<>0) then

+    disp("and is observable",rank(Mo),"Mo has a rank of")

+else

+    disp("and is unobservable",rank(Mo),"Mo has a rank of");

+end

diff --git a/62/CH7/EX7.54/ex_7_54.sce b/62/CH7/EX7.54/ex_7_54.sce
new file mode 100755
index 000000000..8c280828b
--- /dev/null
+++ b/62/CH7/EX7.54/ex_7_54.sce
@@ -0,0 +1,19 @@
+clc;

+A=[1  2;0 3];

+B=[1;1];

+C=[1 -1];

+D=[0];

+Mc=[B A*B];

+if (det(Mc)<>0) then

+    disp("and is controllable",rank(Mc),"Mc has a rank of")

+else

+    disp("and is uncontrollable",rank(Mc),"Mc has a rank of");

+end

+Mo=[C;C*A];

+if (det(Mo)<>0) then

+    disp("and is observable",rank(Mo),"Mo has a rank of")

+else

+    disp("and is unobservable",rank(Mo),"Mo has a rank of");

+end

+Hs=ss2tf(syslin('c',A,B,C,D));

+disp(Hs,"H(s)=")

diff --git a/62/CH7/EX7.7/ex_7_7.sce b/62/CH7/EX7.7/ex_7_7.sce
new file mode 100755
index 000000000..c3ca90c8c
--- /dev/null
+++ b/62/CH7/EX7.7/ex_7_7.sce
@@ -0,0 +1,6 @@
+clc;

+close

+clear;

+z=%s;

+Hz=syslin('d',(1/(1-(3/4)*z^-1+(1/8)*z^-2)));

+ss=tf2ss(Hz);

diff --git a/62/CH7/EX7.8/ex_7_8.sce b/62/CH7/EX7.8/ex_7_8.sce
new file mode 100755
index 000000000..c617f12ee
--- /dev/null
+++ b/62/CH7/EX7.8/ex_7_8.sce
@@ -0,0 +1,6 @@
+clc;

+close

+clear;

+z=%s;

+tf=syslin('d',((1+(1/2)*z^-1)/(1-(3/4)*z^-1+(1/8)*z^-2)));

+ss=tf2ss(tf);

diff --git a/62/CH7/EX7.9/ex_7_9.sce b/62/CH7/EX7.9/ex_7_9.sce
new file mode 100755
index 000000000..7d7df4333
--- /dev/null
+++ b/62/CH7/EX7.9/ex_7_9.sce
@@ -0,0 +1,11 @@
+clc;

+close

+clear;

+z=%s;

+b0=1;

+b1=2;

+b2=3;

+a1=4;

+a2=5;

+tf=syslin('d',((b0+b1*z^-1+b2*z^-2)/(1+a1*z^-1+a2*z^-2)));

+ss=tf2ss(tf);