You are viewing this question as it will appear in the manual grading interface. Return to the normal view when you are done.

Multiply two matrices

Suppose ${\bf A}$ is the following matrix:

${\bf A} = \begin{bmatrix} 0.8 & 0.5 & 0.3\\ 0.4 & 0.1 & 0.4\\ 0.5 & 1.0 & 1.0\\\end{bmatrix}$

In code this is:

1	A = [0.8 0.5 0.3; 0.4 0.1 0.4; 0.5 1.0 1.0];

1	A = {{0.8, 0.5, 0.3}, {0.4, 0.1, 0.4}, {0.5, 1.0, 1.0}};

import numpy as np

A = np.array([[0.8, 0.5, 0.3], [0.4, 0.1, 0.4], [0.5, 1.0, 1.0]])

A = matrix(c(0.8, 0.5, 0.3, 0.4, 0.1, 0.4, 0.5, 1.0, 1.0), nrow = 3, ncol = 3, byrow = TRUE)

from sympy import *

A = Matrix([[0.8, 0.5, 0.3], [0.4, 0.1, 0.4], [0.5, 1.0, 1.0]])

What is the matrix ${\bf B} = {\bf A}{\bf A}^T$?

${\bf B} =$

Note: this is an example of a question generator with randomized parameters, which is used to generate a fixed question variant for an exam. Students receive instant feedback and have retry attempts for partial credit.

${\bf B} =$ [0.98 0.49 1.2; 0.49 0.33 0.70; 1.2 0.70 2.2]

${\bf B} =$ [[0.98, 0.49, 1.2], [0.49, 0.33, 0.70], [1.2, 0.70, 2.2]]

Student view placeholder

In student views this area is used for assessment and score info.

Tools

Staff information

Question

QID:

demo/annotated/mathMatrixMultT

Title:

Multiply two matrices

Variant

Started at:

2026-08-04 20:43:24 (CDT)

Duration:

Show/Hide answer

{
  "B": {
    "_type": "ndarray",
    "_dtype": "float64",
    "_value": [
      [
        0.9800000000000001,
        0.49000000000000005,
        1.2
      ],
      [
        0.49000000000000005,
        0.33000000000000007,
        0.7000000000000001
      ],
      [
        1.2,
        0.7000000000000001,
        2.25
      ]
    ]
  }
}

This box is not visible to students.