initial commit / add all books

21 files changed, 652 insertions, 0 deletions

diff --git a/2279/CH5/EX5.1/Ex5_1.sce b/2279/CH5/EX5.1/Ex5_1.sce
new file mode 100644
index 000000000..cd9426dd7
--- /dev/null
+++ b/2279/CH5/EX5.1/Ex5_1.sce
@@ -0,0 +1,56 @@
+

+

+

+

+

+//Continuous Time Fourier Series Coefficients of 

+//a periodic signal x(t) = sin(2*Wot)

+clear;

+close;

+clc;

+t = 0:0.01:1;

+T = 1;

+Wo = 2*%pi/T;

+xt = sin(2*Wo*t);

+for k =0:4

+  C(k+1,:) = exp(-sqrt(-1)*Wo*t.*k);

+  a(k+1) = xt*C(k+1,:)'/length(t);

+  if(abs(a(k+1))<=0.01) 

+    a(k+1)=0;

+  end

+end

+a =a';

+ak = [-a,a(2:$)]

+for i=1:length(ak)

+    if real(ak(i))== 0 then

+        phase(i)=0;

+    else

+         if i<length(ak)/2 then

+            phase(i)= atan(imag(ak(i))/real(ak(i))); 

+         else

+            phase(i)= -atan(imag(ak(i))/real(ak(i)));

+         end 

+    end

+end

+disp("The fourier series coefficients are...")

+disp(ak)

+disp("magnitude of Fourier series coefficient")

+disp(abs(ak))

+disp("Phase of Fourier series coefficient in radians")

+disp(phase)

+n=-4:4;

+subplot(2,1,1)

+plot(n,abs(ak),'.');

+xtitle("|ak|","k","|ak|");

+subplot(2,1,2)

+for i=1:length(n)

+    if n(i)== -2 then

+    phase(i)=3.14/2;

+    elseif n(i)== 2 then

+    phase(i)= -3.14/2;

+    else

+    phase(i)=0;

+end

+end

+plot(n,phase,'.');

+xtitle("/_ak","k","/_ak");

diff --git a/2279/CH5/EX5.14/Ex5_14.sce b/2279/CH5/EX5.14/Ex5_14.sce
new file mode 100644
index 000000000..7aafaad98
--- /dev/null
+++ b/2279/CH5/EX5.14/Ex5_14.sce
@@ -0,0 +1,37 @@
+//Continuous Time Signal x(t)= exp(-B*t)u(t), t>0

+clear;

+clc;

+close;

+B =1;   

+Dt = 0.005;

+t = 0:Dt:10;

+xt = exp(-B*t);

+Wmax = 2*%pi*1;       

+K = 4;

+k = 0:(K/1000):K;

+W = k*Wmax/K;

+XW = xt* exp(-sqrt(-1)*t'*W) * Dt;

+XW_Mag = abs(XW);

+W = [-mtlb_fliplr(W), W(2:1001)];

+XW_Mag = [mtlb_fliplr(XW_Mag), XW_Mag(2:1001)];

+[XW_Phase,db] = phasemag(XW);

+XW_Phase = [-mtlb_fliplr(XW_Phase),XW_Phase(2:1001)];

+//Plotting Continuous Time Signal

+figure(1)

+plot(t,xt);

+xlabel('t in sec.');

+ylabel('x(t)')

+title('Continuous Time Signal')

+figure(2)

+//Plotting Magnitude Response of CTS

+subplot(2,1,1);

+plot(W,XW_Mag);

+xlabel('Frequency in Radians/Seconds---> W');

+ylabel('abs(X(jW))')

+title('Magnitude Response (CTFT)')

+//Plotting Phase Reponse of CTS

+subplot(2,1,2);

+plot(W,XW_Phase*%pi/180);

+xlabel('                         Frequency in Radians/Seconds---> W');

+ylabel('                                                <X(jW)')

+title('Phase Response(CTFT) in Radians')

diff --git a/2279/CH5/EX5.15/Ex5_15.sce b/2279/CH5/EX5.15/Ex5_15.sce
new file mode 100644
index 000000000..fc0495da8
--- /dev/null
+++ b/2279/CH5/EX5.15/Ex5_15.sce
@@ -0,0 +1,37 @@
+//Continuous Time Signal x(t)= exp(B*t)u(-t), t>0

+clear;

+clc;

+close;

+B =1;  

+Dt = 0.005;

+t = -10:Dt:0;

+xt = exp(B*t);

+Wmax = 2*%pi*1;        

+K = 4;

+k = 0:(K/1000):K;

+W = k*Wmax/K;

+XW = xt* exp(-sqrt(-1)*t'*W) * Dt;

+XW_Mag = abs(XW);

+W = [-mtlb_fliplr(W), W(2:1001)]; 

+XW_Mag = [mtlb_fliplr(XW_Mag), XW_Mag(2:1001)];

+[XW_Phase,db] = phasemag(XW);

+XW_Phase = [-mtlb_fliplr(XW_Phase),XW_Phase(2:1001)];

+//Plotting Continuous Time Signal

+figure(1)

+plot(t,xt);

+xlabel('t in sec.');

+ylabel('x(t)')

+title('Continuous Time Signal')

+figure(2)

+//Plotting Magnitude Response of CTS

+subplot(2,1,1);

+plot(W,XW_Mag);

+xlabel('Frequency in Radians/Seconds---> W');

+ylabel('abs(X(jW))')

+title('Magnitude Response (CTFT)')

+//Plotting Phase Reponse of CTS

+subplot(2,1,2);

+plot(W,XW_Phase*%pi/180);

+xlabel('                         Frequency in Radians/Seconds---> W');

+ylabel('                                                <X(jW)')

+title('Phase Response(CTFT) in Radians')

diff --git a/2279/CH5/EX5.16/Ex5_16.sce b/2279/CH5/EX5.16/Ex5_16.sce
new file mode 100644
index 000000000..39c8f4688
--- /dev/null
+++ b/2279/CH5/EX5.16/Ex5_16.sce
@@ -0,0 +1,27 @@
+//Continuous Time Signal x(t)= exp(-B*abs(t))

+clear;

+clc;

+close;

+B =1;   

+Dt = 0.005;

+t = -4.5:Dt:4.5;

+xt = exp(-B*abs(t));

+Wmax = 2*%pi*1;        

+K = 4;

+k = 0:(K/1000):K;

+W = k*Wmax/K;

+XW = xt* exp(-sqrt(-1)*t'*W) * Dt;

+XW = real(XW);

+W = [-mtlb_fliplr(W), W(2:1001)]; 

+XW = [mtlb_fliplr(XW), XW(2:1001)];

+disp("The given signal is even and it has no phase spectrum")

+subplot(2,1,1);

+plot(t,xt);

+xlabel('t in sec.');

+ylabel('x(t)')

+title('Continuous Time Signal')

+subplot(2,1,2);

+plot(W,XW);

+xlabel('Frequency in Radians/Seconds W');

+ylabel('X(jW)')

+title('Continuous-time Fourier Transform')

diff --git a/2279/CH5/EX5.17/Ex5_17.sce b/2279/CH5/EX5.17/Ex5_17.sce
new file mode 100644
index 000000000..7b7d4a03f
--- /dev/null
+++ b/2279/CH5/EX5.17/Ex5_17.sce
@@ -0,0 +1,29 @@
+//Frequency Response of a Rectangular Waveform

+// x(t)= A, from -T1 to T1

+clear;

+clc;

+close;

+A =1;   

+Dt = 0.005;

+T1 = 4; 

+t = -T1/2:Dt:T1/2;

+for i = 1:length(t)

+  xt(i) = A;

+end

+Wmax = 2*%pi*1;       

+K = 4;

+k = 0:(K/1000):K;

+W = k*Wmax/K;

+xt = xt';

+XW = xt* exp(-sqrt(-1)*t'*W) * Dt;

+XW_Mag = real(XW);

+W = [-mtlb_fliplr(W), W(2:1001)]; 

+XW_Mag = [mtlb_fliplr(XW_Mag), XW_Mag(2:1001)];

+subplot(2,1,1);

+plot(t,xt);

+xlabel('t in sec.');

+title('Contiuous Time Signal x(t)')

+subplot(2,1,2);

+plot(W,XW_Mag);

+xlabel('Frequency in Radians/Seconds');

+title('Continuous-time Fourier Transform  X(jW)')

diff --git a/2279/CH5/EX5.18/Ex5_18.sce b/2279/CH5/EX5.18/Ex5_18.sce
new file mode 100644
index 000000000..b57e4044c
--- /dev/null
+++ b/2279/CH5/EX5.18/Ex5_18.sce
@@ -0,0 +1,22 @@
+// Inverse Continuous Time Fourier Transform

+// X(jW)= 1, from -T1 to T1

+clear;

+clc;

+close;

+// CTFT

+A =1;    

+Dw = 0.005;

+W1 = 4;  

+w = -W1/2:Dw:W1/2;

+for i = 1:length(w)

+  XW(i) = A;

+end

+XW = XW';

+//Inverse Continuous-time Fourier Transform

+t = -3*%pi:%pi/length(w):3*%pi;

+xt =(1/(2*%pi))*XW *exp(sqrt(-1)*w'*t)*Dw;

+xt = real(xt);

+figure

+plot(t,xt);

+xlabel('            t Sec');

+title('Time domain signal x(t)')

diff --git a/2279/CH5/EX5.19/Ex5_19.sce b/2279/CH5/EX5.19/Ex5_19.sce
new file mode 100644
index 000000000..f61779753
--- /dev/null
+++ b/2279/CH5/EX5.19/Ex5_19.sce
@@ -0,0 +1,29 @@
+//frequency response of impulse signal

+clear;

+clc;

+close;

+A =1;    

+Dt = 0.005;

+T1 = 4; 

+Wo=2//Assume Wo=2

+t = -T1/2:Dt:T1/2;

+for i = 1:length(t)

+    xt(i)=sin(Wo*t(i));

+end

+Wmax = 2*%pi*1;        

+K = 4;

+k = 0:(K/1000):K;

+W = k*Wmax/K;

+xt = xt';

+XW = xt* exp(-sqrt(-1)*t'*W) * Dt;

+XW_Mag = real(XW);

+W = [-mtlb_fliplr(W), W(2:1001)]; 

+XW_Mag = [mtlb_fliplr(XW_Mag), XW_Mag(2:1001)];

+subplot(2,1,1);

+plot(t,xt);

+xlabel('t in sec.');

+title('Contiuous Time Signal x(t)')

+subplot(2,1,2);

+plot(W,XW_Mag);

+xlabel('Frequency in Radians/Seconds');

+title('Continuous-time Fourier Transform  X(jW)')

diff --git a/2279/CH5/EX5.2/Ex5_2.sce b/2279/CH5/EX5.2/Ex5_2.sce
new file mode 100644
index 000000000..f88b3868e
--- /dev/null
+++ b/2279/CH5/EX5.2/Ex5_2.sce
@@ -0,0 +1,43 @@
+//Continuous Time Fourier Series Coefficients of 
+//a periodic signal x(t) = cos(Wot)
+clear;
+close;
+clc;
+t = 0:0.01:1;
+T = 1;
+Wo = 2*%pi/T;
+xt = cos(Wo*t);
+x1t=cos(Wo*-t);
+for k =0:2
+  C(k+1,:) = exp(-sqrt(-1)*Wo*t.*k);
+  a(k+1) = xt*C(k+1,:)'/length(t);
+  if(abs(a(k+1))<=0.01) 
+    a(k+1)=0;
+  end
+end
+a =a';
+ak = [-a,a(2:$)]
+disp("The fourier series coefficients are...")
+disp(ak)
+disp("magnitude of Fourier series coefficient")
+disp(abs(ak))
+n=-2:2;
+subplot(2,1,1)
+plot(n,abs(ak),'.');
+xtitle("Magnitude Spectrum","k","|ak|");
+if xt== x1t then
+    disp("The Given signal is even. It has no phase spectrum");
+else
+for i=1:length(ak)
+    if real(ak(i))== 0 then
+        phase(i)=0;
+    else
+        phase(i)=atan(imag(ak(i))/real(ak(i)));
+    end
+end
+disp("Phase of Fourier series coefficient in radians")
+disp(phase)
+subplot(2,1,2)
+plot(n,phase,'.');
+xtitle("Phase Spectrum","k","ak in radians");
+end
diff --git a/2279/CH5/EX5.20/Ex5_20.sce b/2279/CH5/EX5.20/Ex5_20.sce
new file mode 100644
index 000000000..fc26d738c
--- /dev/null
+++ b/2279/CH5/EX5.20/Ex5_20.sce
@@ -0,0 +1,28 @@
+// Inverse Continuous Time Fourier Transform

+// X(jW)= 2*pi, at W=0

+clear;

+clc;

+close;

+// CTFT

+A =1;    

+Dw = 0.005;

+W1 = 4;  

+w = -W1/2:Dw:W1/2;

+for i = 1:length(w)

+    if w(i)==0 then

+  XW(i) = 2*%pi;

+else

+    XW(i)=0;

+end

+end

+XW = XW';

+subplot(2,1,1)

+plot(w,XW)

+//Inverse Continuous-time Fourier Transform

+t = -3*%pi:%pi/length(w):3*%pi;

+xt =(1/(2*%pi))*XW *exp(sqrt(-1)*w'*t)*Dw;

+xt = real(1+xt);

+subplot(2,1,2)

+plot(t,xt);

+xlabel('            t Sec');

+title('Time domain signal x(t)')

diff --git a/2279/CH5/EX5.21/Ex5_21.sce b/2279/CH5/EX5.21/Ex5_21.sce
new file mode 100644
index 000000000..f50d54b18
--- /dev/null
+++ b/2279/CH5/EX5.21/Ex5_21.sce
@@ -0,0 +1,26 @@
+// Inverse Continuous Time Fourier Transform

+// X(jW)= 2*pi, at W=Wo

+clear;

+clc;

+close;

+// CTFT

+A =1;    

+Dw = 0.005;

+W1 = 4;  

+Wo=2//Assume Wo=2

+w = -W1/2:Dw:W1/2;

+for i = 1:length(w)

+    if w(i)==Wo then

+  XW(i) = 2*%pi;

+else

+    XW(i)=0;

+end

+end

+XW = XW';

+//Inverse Continuous-time Fourier Transform

+t = -3*%pi:%pi/length(w):3*%pi;

+xt =(1/(2*%pi))*XW *exp(sqrt(-1)*w'*t)*Dw;

+xt = real(1+xt);

+plot(t,xt);

+xlabel('            t Sec');

+title('Time domain signal x(t)')

diff --git a/2279/CH5/EX5.22/Ex5_22.sce b/2279/CH5/EX5.22/Ex5_22.sce
new file mode 100644
index 000000000..af89d94f6
--- /dev/null
+++ b/2279/CH5/EX5.22/Ex5_22.sce
@@ -0,0 +1,26 @@
+// Inverse Continuous Time Fourier Transform

+// X(jW)= 2*pi, at W=-Wo

+clear;

+clc;

+close;

+// CTFT

+A =1;    

+Dw = 0.005;

+W1 = 4;  

+Wo=2//Assume Wo=2

+w = -W1/2:Dw:W1/2;

+for i = 1:length(w)

+    if w(i)==-Wo then

+  XW(i) = 2*%pi;

+else

+    XW(i)=0;

+end

+end

+XW = XW';

+//Inverse Continuous-time Fourier Transform

+t = -3*%pi:%pi/length(w):3*%pi;

+xt =(1/(2*%pi))*XW *exp(sqrt(-1)*w'*t)*Dw;

+xt = real(1+xt);

+plot(t,xt);

+xlabel('            t Sec');

+title('Time domain signal x(t)')

diff --git a/2279/CH5/EX5.24/Ex5_24.sce b/2279/CH5/EX5.24/Ex5_24.sce
new file mode 100644
index 000000000..cf324aad2
--- /dev/null
+++ b/2279/CH5/EX5.24/Ex5_24.sce
@@ -0,0 +1,14 @@
+// Continuous Time Fourier Transforms of 

+// Sinusoidal waveforms sin(Wot) 

+clear

+clc;

+close;

+T1 = 2;

+T = 4*T1;

+Wo = 2*%pi/T;

+W = [-Wo,0,Wo];

+ak = (2*%pi*Wo*T1/%pi)/sqrt(-1);

+XW = [-ak,0,ak];

+plot(W,-imag(XW),'.');

+xlabel('                                                      W');

+xtitle('CTFT of sin(Wot)','W','X(jW)')

diff --git a/2279/CH5/EX5.25/Ex5_25.sce b/2279/CH5/EX5.25/Ex5_25.sce
new file mode 100644
index 000000000..350ed7339
--- /dev/null
+++ b/2279/CH5/EX5.25/Ex5_25.sce
@@ -0,0 +1,16 @@
+// Continuous Time Fourier Transforms of 

+// Sinusoidal waveforms cos(Wot)

+clear;

+clc;

+close;

+// CTFT

+T1 = 2;

+T = 4*T1;

+Wo = 2*%pi/T;

+W = [-Wo,0,Wo];

+ak = (2*%pi*Wo*T1/%pi);

+XW =[ak,0,ak];

+plot(W,abs(XW),'.');

+xlabel('                        W');

+xtitle('CTFT of cos(Wot)','W','X(jW)')

+

diff --git a/2279/CH5/EX5.3/Ex5_3.sce b/2279/CH5/EX5.3/Ex5_3.sce
new file mode 100644
index 000000000..f3de06d08
--- /dev/null
+++ b/2279/CH5/EX5.3/Ex5_3.sce
@@ -0,0 +1,34 @@
+//Continuous Time Fourier Series Coefficients of 
+//a periodic signal x(t) = 5*cos((%pi/2*t)+(%pi/6))
+clear;
+close;
+clc;
+t = 0:0.01:1;
+T = 1;
+Wo = 2*%pi/T;
+xt = cos((%pi/2*t)+(%pi/6))
+x1t=cos((%pi/2*-t)+(%pi/6))
+
+//x(t) is expanded according to Euler's theorem
+x=5/2*(exp(%i*(%pi/2*t+%pi/6))+exp(-%i*(%pi/2*t+%pi/6)));
+a1=5/2*exp(%i*%pi/6);
+a_1=5/2*exp(-%i*%pi/6);
+ak=[zeros(1,5) a_1 0 a1 zeros(1,5)];
+k=-6:6;
+disp("The fourier series coefficients are...")
+disp(ak)
+disp("magnitude of Fourier series coefficient")
+disp(abs(ak))
+subplot(2,1,1)
+plot(k,abs(ak),'.');
+xtitle("Magnitude Spectrum","k","|ak|");
+if xt== x1t then
+    disp("The Given signal is even. It has no phase spectrum");
+else
+    phase=[zeros(1,5) atan(imag(a_1)/real(a_1)) 0 atan(imag(a1)/real(a1))  zeros(1,5)];
+    disp("Phase of Fourier series coefficient in radians")
+    disp(phase)
+    subplot(2,1,2)
+    plot(k,phase,'.');
+    xtitle("Phase Spectrum","k","ak in radians");
+end
diff --git a/2279/CH5/EX5.32/Ex5_32.sce b/2279/CH5/EX5.32/Ex5_32.sce
new file mode 100644
index 000000000..43cb6362a
--- /dev/null
+++ b/2279/CH5/EX5.32/Ex5_32.sce
@@ -0,0 +1,21 @@
+//CTFT of Periodic Impulse Train

+clear;

+clc;

+close;

+// CTFT

+T = -4:4;;

+T1 = 1; 

+xt = ones(1,length(T));

+ak = 1/T1;

+XW = 2*%pi*ak*ones(1,length(T));

+Wo = 2*%pi/T1;

+W = Wo*T;

+figure

+subplot(2,1,1)

+plot2d3('gnn',T,xt); 

+xlabel('                    t');

+title('Periodic Impulse Train')

+subplot(2,1,2)

+plot2d3('gnn',W,XW);

+xlabel('                   t');

+title('CTFT of Periodic Impulse Train')

diff --git a/2279/CH5/EX5.37/Ex5_37.sce b/2279/CH5/EX5.37/Ex5_37.sce
new file mode 100644
index 000000000..bc805dab7
--- /dev/null
+++ b/2279/CH5/EX5.37/Ex5_37.sce
@@ -0,0 +1,37 @@
+//Continuous Time Signal x(t)= 0.5*exp(-B*t*0.5)u(t), t>0

+clear;

+clc;

+close;

+B =1;   

+Dt = 0.005;

+t = 0:Dt:10;

+h = 0.5*exp(-B*t*0.5);

+Wmax = 2*%pi*1;       

+K = 4;

+k = 0:(K/1000):K;

+W = k*Wmax/K;

+XW = h* exp(-sqrt(-1)*t'*W) * Dt;

+XW_Mag = abs(XW);

+W = [-mtlb_fliplr(W), W(2:1001)];

+XW_Mag = [mtlb_fliplr(XW_Mag), XW_Mag(2:1001)];

+[XW_Phase,db] = phasemag(XW);

+XW_Phase = [-mtlb_fliplr(XW_Phase),XW_Phase(2:1001)];

+//Plotting Continuous Time Signal

+figure(1)

+plot(t,h);

+xlabel('t in sec.');

+ylabel('x(t)')

+title('Continuous Time Signal')

+figure(2)

+//Plotting Magnitude Response of CTS

+subplot(2,1,1);

+plot(W,XW_Mag);

+xlabel('Frequency in Radians/Seconds---> W');

+ylabel('abs(X(jW))')

+title('Magnitude Response (CTFT)')

+//Plotting Phase Reponse of CTS

+subplot(2,1,2);

+plot(W,XW_Phase*%pi/180);

+xlabel('                         Frequency in Radians/Seconds---> W');

+ylabel('                                                <X(jW)')

+title('Phase Response(CTFT) in Radians')

diff --git a/2279/CH5/EX5.4/Ex5_4.sce b/2279/CH5/EX5.4/Ex5_4.sce
new file mode 100644
index 000000000..ee824c03f
--- /dev/null
+++ b/2279/CH5/EX5.4/Ex5_4.sce
@@ -0,0 +1,35 @@
+//Continuous Time Fourier Series Coefficients of 

+//a periodic signal x(t) = 1+sin(6t)+cos(4t)

+clear;

+close;

+clc;

+t = 0:0.01:1;

+xt = 1+sin(6*t)+cos(4*t);

+x_t = 1+sin(6*-t)+cos(4*-t);

+

+//x(t) is expanded according to Euler's theorem

+x=1+(1/2)*exp(%i*4*t)+(1/2)*exp(-%i*4*t)+(1/(2*%i))*exp(%i*6*t)-(1/(2*%i))*exp(-%i*6*t);

+a0=1;

+a2=(1/2)

+a_2=(1/2)

+a3=(1/(2*%i));

+a_3=-(1/(2*%i));

+ak=[zeros(1,5) a_3 a_2 0 a2 a3 zeros(1,5)];

+k=-7:7;

+disp("The fourier series coefficients are...")

+disp(ak)

+disp("magnitude of Fourier series coefficient")

+disp(abs(ak))

+subplot(2,1,1)

+plot(k,abs(ak),'.');

+xtitle("Magnitude Spectrum","k","|ak|");

+if xt== x_t then

+    disp("The Given signal is even. It has no phase spectrum");

+else

+    phase=[zeros(1,6) %pi/2 0 -%pi/2  zeros(1,6)];

+    disp("Phase of Fourier series coefficient in radians")

+    disp(phase)

+    subplot(2,1,2)

+    plot(k,phase,'.');

+    xtitle("Phase Spectrum","k","ak in radians");

+end

diff --git a/2279/CH5/EX5.5/Ex5_5.sce b/2279/CH5/EX5.5/Ex5_5.sce
new file mode 100644
index 000000000..5f93e2cfb
--- /dev/null
+++ b/2279/CH5/EX5.5/Ex5_5.sce
@@ -0,0 +1,41 @@
+//Fourier Series coefficients of the signal x(t)

+//Assume the period of the signal T=10

+clc

+clear

+close

+T=1;

+To=1/4;

+//Assume the magnitude of the signal A=1

+A=1;

+t=-10:0.01:10;

+for i=1:length(t)

+    if t>To & t<-To then

+        x(i)=0;

+    else

+        x(i)=A;

+    end

+end

+

+Wo=2*%pi;

+

+k=-5:5

+for i=1:length(k)

+    if k(i)==0 then

+        ak(i)=1.5;

+    else

+        ak(i)=(sin(k(i)*%pi/2))/(k(i)*%pi);

+    end

+end

+

+disp("The fourier series coefficients are...")

+disp(ak)

+disp("magnitude of Fourier series coefficient")

+disp(abs(ak))

+disp("the givem signal is even and so it has no phase spectrum")

+//PLotting frequency spectrum 

+subplot(2,1,2)

+plot(k,abs(ak),'.');

+xtitle("Magnitude Spectrum","k","|ak|");

+subplot(2,1,1)

+plot(k,ak,'.');

+xtitle("Ak","k","ak");

diff --git a/2279/CH5/EX5.6/Ex5_6.sce b/2279/CH5/EX5.6/Ex5_6.sce
new file mode 100644
index 000000000..a08627cd1
--- /dev/null
+++ b/2279/CH5/EX5.6/Ex5_6.sce
@@ -0,0 +1,21 @@
+//Fourier Series coefficients for Impulse train

+clc

+clear

+close

+//Assume period of the impulse train T=2

+T=2;

+t=-5*T:T:5*T;

+for i=1:length(t)

+    x(i)=1;

+end

+//Using sifting property of the impulse signal 

+k=-10:10

+for i=1:length(k)

+    ak(i)=1/T;

+end

+subplot(2,1,1)

+plot(t,x,'.')

+xtitle("Impulse train","t","x(t)")

+subplot(2,1,2)

+plot(k,ak,'.')

+xtitle("Fourier coefficients of impulse train","k","ak")

diff --git a/2279/CH5/EX5.7/Ex5_7.sce b/2279/CH5/EX5.7/Ex5_7.sce
new file mode 100644
index 000000000..b1a9f8517
--- /dev/null
+++ b/2279/CH5/EX5.7/Ex5_7.sce
@@ -0,0 +1,50 @@
+//Fourier Series coefficients of half-wave rectifier output
+//Assume the period of the signal T=1
+t=-0.5:0.01:1;
+T = 1;
+for i=1:length(t)
+    if t(i)<T/2 then
+        x(i)=sin(2*%pi*t(i));
+    else
+        x(i)=0;
+    end
+end
+k=-10:10;
+for i=1:length(k)
+    if k(i)==1 then
+        ak(i)=1/(4*%i);
+    elseif k(i)==-1
+        ak(i)=-1/(4*%i);
+    else
+        ak(i)=(cos(k(i)*%pi/2)*exp(-k(i)*%pi/2*-%i))/(%pi-(%pi*k(i)*k(i)));
+    end
+end
+
+
+disp("The fourier series coefficients are...")
+disp(ak)
+disp("magnitude of Fourier series coefficient")
+disp(abs(ak))
+//PLotting frequency spectrum 
+subplot(2,1,1)
+plot(k,abs(ak),'.');
+xtitle("Magnitude Spectrum","k","|ak|");
+for i=1:length(k)
+    if k(i)==0 | k(i)==3 | k(i)==-3 | k(i)==-5 |k(i)==5 then
+        phase(i)=0;
+    elseif k(i)==-1 then
+            phase(i)=%pi/2;
+    elseif k(i)==1  then
+             phase(i)=-%pi/2;
+    elseif k(i)==-2 | k(i)==-4
+          phase(i)=%pi;
+    elseif k(i)==2 | k(i)==4
+            phase(i)=-%pi;
+    else
+            phase(i) =  0;
+    end        
+end
+subplot(2,1,2)
+plot(k,phase,'.');
+xtitle("Phase Spectrum","k","angle(ak)");
+disp(phase)
\ No newline at end of file
diff --git a/2279/CH5/EX5.8/Ex5_8.sce b/2279/CH5/EX5.8/Ex5_8.sce
new file mode 100644
index 000000000..181ba1ef2
--- /dev/null
+++ b/2279/CH5/EX5.8/Ex5_8.sce
@@ -0,0 +1,23 @@
+//Fourier Series coefficients of half-wave rectifier output

+//Assume the period of the signal T=1

+t=-0.5:0.01:0.5;

+for i=1:length(t)

+    if t(i)<-0.25 & t(i)>0.25 then

+        x(i)=-1;

+    else

+        x(i)=1;

+    end

+end

+k=-10:10;

+for i=1:length(k)

+    if k(i)==0 then

+        ak(i)=0;

+    else

+        ak(i)=(%i*((2-(-1)^k(i))*exp(-%i*k(i)*%pi/2)-exp(%i*k(i)*%pi/2)))/(k(i)*2*%pi);

+    end

+end

+

+disp("The fourier series coefficients are...")

+disp(ak)

+plot(k,ak,'.')

+xtitle("Fourier Coefficients","k","ak")