[FIXED] Modify the values of a python list / array substituted in a polynomial equation

Issue

I need help in creating a statement with this initial set of positive numbers for the roots of an equation. I have to substitute them to my polynomial equation to determine if that certain number is a root or not. This is what I came up so far:

k = [4.0, 2.0, 1.0054, 0.9946] # Set of roots (sign-less)
pol = x**4 + 6*x**3 + 7*x**2 - 6*x - 8 # Polynomial equation
(pol(k)) <= abs(1)

With the output:

array([False, False,  True,  True])

Basically, what I wanted is to print those True as it is and reverse the sign of those False, since the latter gave a very large value and therefore might not be the root to my equation. Desired output should be like this:

[-4.0, -2.0, 1.0054, 0.9946]

I'm somewhat stuck in my third line since I could not think how the next step shall be executed. Any help would be appreciated. I am very new in python coding. Thanks!

Solution

code :

k = [4.0, 2.0, 1.0054, 0.9946]

array = ([False, False,  True,  True])

if len(k)==len(array):
    for i in range(len(k)):
        if array[i] == False:
            k[i]-=(2*k[i])

print(k)

**output : **

[-4.0, -2.0, 1.0054, 0.9946]

have a look, this code will update your k list to desired form.

Answered By - Omkar Kalantre