//5.6
clc;
disp('When the power delivered is 80% we have')
//0.8=1/(%pi)*(%pi-alph+sin(2*alph)/2)
//on solving
alph=60.5;
printf("Firing angle=%.1f degree",alph)
disp('When the power delivered is 30% we have')
//0.3=1/(%pi)*(%pi-alph+sin(2*alph)/2)
//on solving
alph=108.6;
printf("Firing angle=%.1f degree",alph)