printf(" given d1=0.8 and d2=0.2"); 
printf(" we have to dtermine the time constant T for which the damping ratio is reduced from 0.8 to 0.2");
d1=0.8;
d2=0.2;
c=d1/d2;
disp(c^2,"T2/T1=");
printf("hence, the original time constant T1 should be multiplied by 16, then the damping ratio becomes 0.2");