All Tasks
Matrix - Linear System Equations
A magic square is a square table of natural numbers, side $n$, where the sum of row numbers, column numbers, and diagonal numbers is constant, none of which repeats.
Enter the values of $a$, $b$ and $c$ so that
$A=\begin{bmatrix}
a&2&9\\8&b&4\\3&10&c
\end{bmatrix}$ be a matrix representing a magic square.
# System of linear equations
Modeling
13
Power of a matrix 2
Let $A=\begin{bmatrix} -0.5& -1 & 0.5\\1 &0.5 & -1\\0.5 &0 &0.5\end{bmatrix}$, $M=A^2$ and $N=A^3$.
The entries $m_{32}$ and $n_{23}$ of $M$ and $N$ are (respectively) equal to:
# Operation
Reasoning
13
Matrix operations 1
Consider identity matrix $I_3$ and the matrices $$A=\begin{bmatrix}
1&-1&2\\-0.5&0&1
\end{bmatrix},\quad B=\begin{bmatrix}
1&1&-1\\2& 0& 0\\-1&0&1
\end{bmatrix}$$
$$C=\begin{bmatrix}
1&0\\2& -1\\-1&1
\end{bmatrix}$$
Check which of the following operations are possible:
$(a1)\ C-2A^T\quad (a2)\ 3A-C\quad (a3)\ (I_3+2B)^T\quad$
# Operation
Training
13
Operations mix
Consider the real matrices $A=[a_{ij}],\ i,j=1,2,3:\ \
a_{ij}=\left\{
\begin{array}{l}
i-2, \quad i>j\\
0, \quad \quad i=j\\
ij+1, \quad i<j
\end{array}
\right.
$,
$B=\begin{bmatrix} \frac{1}{3}&\frac{2}{3}&7\\\frac{1}{3}&-\frac{1}{3}&1\\3&3&\frac{1}{3}\end{bmatrix}$,
$C=\begin{bmatrix} 1&2\\0&1\\-1&0\end{bmatrix}$ and
$D=\begin{bmatrix} 1&2&3\\-1&0&1\end{bmatrix}$.
Compute $M=A^2 - 3B + (CD)^T$.
# Operation
Learning
13
Linear system equations and Gauss elimination method
Applying the Gauss elimination's method, the solution of the linear system equations
$$
\left\{
\begin{array}{l}
2x+y-z=1\\
-x+2y-3z=1\\
4x+z=2
\end{array}
\right.
$$
is:
# Matrices
# System of linear equations
Training
13
Matrix representation of a system of linear equations
Consider the system of linear equations
$$
\left\{
\begin{array}{l}
x-y+2z=3\\
-3y-z=-5\\
3x-y+4z=7
\end{array}
\right.
$$
The second and the fourth columns of the matrix that represents the system are:
# System of linear equations
Training
13