1 files changed, 36 insertions, 0 deletions
diff --git a/257/CH8/EX8.20/example_8_20.sce b/257/CH8/EX8.20/example_8_20.sce
new file mode 100644
index 000000000..794126e0a
--- /dev/null
+++ b/257/CH8/EX8.20/example_8_20.sce
@@ -0,0 +1,36 @@
+s=%s
+syms K
+m=s^4+6*s^3+30*s^2+60*s+K
+cof_a_0 = coeffs(m,'s',0);
+cof_a_1 = coeffs(m,'s',1);
+cof_a_2 = coeffs(m,'s',2);
+cof_a_3 = coeffs(m,'s',3);
+    
+r=[cof_a_0 cof_a_1 cof_a_2 cof_a_3] 
+
+n=length(r);
+routh=[r([4,2]);r([3,1])];
+routh=[routh;-det(routh)/routh(2,1),0];
+t=routh(2:3,1:2); //extracting the square sub block of routh matrix
+routh=[routh;-det(t)/t(2,1),0]
+disp(routh,"rouths tabulation=")
+routh(3,1)=0  //For marginaly stable system
+
+disp("for all closed loop poles to left of -1")
+s=%s
+syms K
+m=s^4+2*s^3+18*s^2+14*s+K-35
+cof_a_0 = coeffs(m,'s',0);
+cof_a_1 = coeffs(m,'s',1);
+cof_a_2 = coeffs(m,'s',2);
+cof_a_3 = coeffs(m,'s',3);
+    
+r=[cof_a_0 cof_a_1 cof_a_2 cof_a_3] 
+
+n=length(r);
+routh=[r([4,2]);r([3,1])];
+routh=[routh;-det(routh)/routh(2,1),0];
+t=routh(2:3,1:2); //extracting the square sub block of routh matrix
+routh=[routh;-det(t)/t(2,1),0]
+disp(routh,"rouths tabulation=")
+routh(3,1)=0  //For marginaly stable system
+\ No newline at end of file