2.3

2-3.py

import math
balance=10050000
annualInterestRate=0.2



monthly=annualInterestRate / 12
lo=balance/12
hi=balance+(balance * annualInterestRate)


error=10000
while(error>0.01):

    b=balance
    c=(lo+hi)/2
    print "C: ", round(c,2)
    for i in range(1,13):
        b=(b-c)*(1+monthly)
    error=math.sqrt(math.pow((b-0), 2))
    if b>0:
        lo=c
        c=(lo+hi)/2
    elif b<0:
        hi=c
        c=(lo+hi)/2
    b=(b-c)*(1+annualInterestRate/12)

print "Lowest Payment:", round(c, 2)