Please help me out to calculate the values of R1 & R2. what is the formula or how to derive it. i am attaching the circuit design. thanks

Design task:
Target specification for Current Limiting circuit
(i) Io [max allowed current] = 2A
(ii) Isc [fold back current] = 0.5A
(iii) Regulated output voltage Vo = 12V

d. Calculate the value of Rs.
Io = 2A
VbeM = 0.6A

From Ohm’s Law
Rs = VbeM¬¬ / Io
Rs = 0.6 / 2
Rs = 0.3Ω

e. Calculate the values of R1 & R2 to achieve the above data?

 

Page 11, table 7

 

thanks alot #12.