//chapter 20
//example 20.3
//page 906
printf("\n")
printf("given")
R1=2.2*10^3;R2=1.5*10^3;R3=120;Vt=1.5;
disp(" with R2 contact at center")
Vak=Vt*((R1+R2+R3)/(R3+.5*R2))
disp(" with R2 contact at zero")
Vak=Vt*((R1+R2+R3)/R3)