from math import sqrt

# Fixed-point iteration for computing the square root of a
# Does not work for all values of a
# n_it is number of fixed-point iterations
# x is initial guess
def fix_root(a,x,n_it):

    true_solution=sqrt(a)

    print '\n \t approximation', '\t error'
    for k in range(n_it):
        x=-x*x+a+x
        error=abs(true_solution-x)
        print '\t %f \t %f' % (x,error)