//chapter 18
//example 18.7
//page 7
printf("\n")
printf("given")
Isc=100*10^-3;Vr10=.5;Vo=12;
R10=Vr10/Isc
R10=4.7;//use standard value
Il=200*10^-3;
Vr10=Il*R10
Vr11=Vr10-.5
I11=1*10^-3;
R11=Vr11/I11
R12=(Vo+Vr10-Vr11)/I11