前言

嗨，这本课本没答案，有些计算题都不知道对不对，只能靠计算机辅助一下啦。

chapter1

q_6

import numpy as np


def question_c():
    a = np.mat([[1, 2], [4, -3]])
    result = 2 * np.dot(np.dot(a, a), a) - 4 * a + 5
    print(result)
    """
    [[ -13   57]
     [ 109 -117]]
    """


def question_d():
    a = np.mat([[1, 2], [4, -3]])
    result = np.dot(a, a) + 2 * a + 11
    print(result)
    """
    [[22 11]
     [11 22]]
    """


if __name__=="__main__":
    # question_c()
    question_d()

q_22

需要引入这篇博客 python输出高斯消元法求解行列式的过程的代码，并把那个文件命名为 echelon_form.py

from echelon_form import *


if __name__ == "__main__":
    a = [[1, 0, 2, 1, 0, 0], [2, -1, 3, 0, 1, 0], [4, 1, 8, 0, 0, 1]]
    a = make_matrix(a)

    cofficient_cols_num = 3
    echelon_form(a, cofficient_cols_num, reduce_echelon_form=True)

输出:

prc_row, prc_col: 0 0
process 0. simplify row 1
------------------------------------------------------------
         1         0         2         1         0         0
         0        -1        -1        -2         1         0
         0         1         0        -4         0         1

prc_row, prc_col: 1 1
process 1. simplify row 1
------------------------------------------------------------
         1         0         2         1         0         0
         0         1         1         2        -1         0
         0         0        -1        -6         1         1

prc_row, prc_col: 2 2
process 2. simplify row 1
------------------------------------------------------------
         1         0         0       -11         2         2
         0         1         0        -4         0         1
         0         0         1         6        -1        -1