def poly_f(x, c):
    """Calculate the value of the f(x) based on the polynomial method provided by the question:
    f(t) = c[k-1] * pow(t, k-1) + c[k-2] * pow(t, k-2) + ... + c[0] * 1
    """
    f_x = 0
    for i in range(len(c)):
        f_x += pow(x, i) * c[i]
    return f_x