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+// Ex 72 Page 411
+
+clc;clear;close;
+// Given
+R=200;//ohm
+L=2;//H
+C=5*10**-6;//F
+
+
+
+if R<2*sqrt(L/C) then
+printf("Since R<2sqrt(L/C), the circuit is originally oscillatory.")
+end
+
+a=R/(2*L)
+omega = sqrt(1/L/C-R^2/4/L^2);//rad/s
+//i=Im*%e**(-a*t)*sin(omega*t+fi)
+//at t=0 sec
+i0=0;//A
+vc=10;//V
+fi=asin(i0);//degree
+//L*di/dt=vc at t=0
+Im=poly([0],'Im')
+function i=current(t)
+    i=Im*expm(-a*t)*sin(omega*t+fi)
+endfunction
+//i=Im*expm(-a*t)*sin(omega*t+fi)
+LdiBYdt=L*numderivative(current,0)
+temp = coeff(LdiBYdt)
+Im=vc/temp(2)
+printf("\n\n Expression for current :\n  i = %.3f*exp(-%dt)*sin(%.1ft)",Im,a,omega)
+Rn=2*sqrt(L/C);//ohm
+Rad=Rn-R;//ohm
+printf("\n\n Resistance required = %d ohm",Rad)