Answer:
a) Eo = -C/ro + D exp(-ro/p)
1) dEN/dr = C/r² - D exp(-r/p)
2) Eo + C/ro = -Dexp(-ro/p)
C/ro = -Dexp(-ro/p) - Eo
∴ C = -ro(Dexp(-ro/p) + Eo)
3) EN = -(-ro(Dexp(-ro/p) + Eo)/r + Dexp(-r/p)
EN = ro(Dexp(-ro/p) - roEo/r + Dexp(-r/p)
EN + roEo/r = ro(Dexp(-ro/p) + Dexp(-r/p)
roEo/r = D(exp(-ro/p) + exp(-r/p) - EN
∴ Eo= r{D(exp(-ro/p) + exp(-ro/p) - EN}/ro
b)
Explanation: