import numpy as np
import matplotlib.pyplot as plt

def bisection(a,b,f,err): #This is the code for the bisection method.
    c = (a+b)/2
    while c - a > err:
        if f(c) == 0:
            return c
        elif f(a)*f(c) > 0:
            a = c
        else:
            b = c
        c = (a+b)/2
    return c

x =np.linspace(1,2,1000) #We are graphing our compound interest formulaa to get a sense of our boundards a and b for our bisection code.
y = 787.5*(1+x/12)**19 - ((-95.3*12)/x)*(1-(1+x/12)**19)
plt.plot(x,y)
plt.show()

def f(x): #We are defining the function to which the bisection code will run on.
    return 787.5*(1+x/12)**19 - ((-95.3*12)/x)*(1-(1+x/12)**19)

bisection(1,2,f,0.0001) #Interest Rate.