Matrices and determinants

2000017210

Level: 
B
In the following matrix, what is the position of the entry with the largest value? \[ \left (\array{ 1+2& \sin \frac{\pi}4& \mathrm{tg}\,\frac{3\pi}4\cr 3+\cos \frac{\pi}2 & 2^{\sqrt3} & 5+\mathrm{tg} (-\pi)\cr \sqrt{23}& 3-4 & \sin 2\pi -2 } \right ) \]
It lays above the main diagonal.
It lays on the main diagonal.
It lays under the main diagonal.
It lays on the counterdiagonal.

2000017206

Level: 
B
For what values of \(a\), \(b\) and \(c\) is the matrix \[ \left (\array{ a-b+c& 0 & a-2b\cr a+c-2b & 2^{a-2b} & 0\cr 2b-a & 0 & c-a+3b } \right ) \] an identity matrix?
\(a=2\), \(b=1\), \(c=0\)
\(a=1\), \(b=2\), \(c=1\)
\(a=2\), \(b=1\), \(c=3\)
\(a=1\), \(b=1\), \(c=0\)

2000017205

Level: 
A
Which of the given matrices is the matrix \((m_{i,j})\), where \(i=1, \dots, 3\) and \(j=1,\dots,3\) with \(m_{i,j}=i+j+1\)?
\( \left (\array{ 3& 4 & 5\cr 4 & 5 & 6\cr 5 & 6 & 7 } \right ) \)
\( \left (\array{ 2& 3 & 4\cr 3 & 4 & 5\cr 4 & 5 & 6 } \right ) \)
\( \left (\array{ 3& 4 & 5\cr 3 & 4 & 5\cr 4 & 5 & 6 } \right ) \)
\( \left (\array{ 2& 3 & 4\cr 2 & 3 & 4\cr 4 & 5 & 6 } \right ) \)

2000017204

Level: 
A
Which of the given matrices is the matrix \((m_{i,j})\), where \(i=1, \dots, 3\) and \(j=1,~2\)?
\( \left (\array{ 8& 7\cr 6 & 5\cr 4 & 3\cr } \right ) \)
\( \left (\array{ 8& 7 & 6\cr 5 & 4 & 3\cr } \right ) \)
\( \left (\array{ 8& 7 & 6\cr 5 & 4 & 3\cr 2 & 1 & 0 } \right ) \)
\( \left (\array{ 8& 7 \cr 6 & 5 \cr } \right ) \)

2000017203

Level: 
A
Which of the given matrices have the same entry at the position \( (1,2)\)? \[ K=\left (\array{ 1& \sqrt2 & 3 & \sqrt5\cr \sqrt3& 2 & 1 & 5\cr 4& 1 & 1& 0\cr } \right ), \quad L=\left (\array{ 1& \sqrt2 & 3\cr \sqrt3 & 2 & 1\cr 4 & 1& 1\cr \sqrt5 & 5& 0 } \right ), \] \[ M=\left (\array{ \sqrt3& 2 & 1\cr \sqrt3 & 4 & 0 } \right ), \quad N=\left (\array{ 1& \sqrt3 & 4\cr \sqrt3 & 2 & 1 \cr 3 & 1 & 1 \cr \sqrt5 & 5 & 0 } \right ) \]
\(K\) and \(L\)
\(K\), \(L\) and \(N\)
\(K\), \(L\), \(M\), and \(N\)
\(L\) and \(N\)

2000017202

Level: 
A
Which of the given matrices \(K\), \(L\), \(M\), and \(N\) have the same main diagonal? \[ K=\left (\array{ 1& 7 & 8\cr 4 & 2 & 9 \cr 5 & 6 & 3 } \right ),\quad L=\left (\array{ 3& 9 & 8\cr 4 & 2 & 7 \cr 5 & 6 & 1 } \right ), \] \[ M=\left (\array{ 1& 7 & 9\cr 5 & 2 & 8 \cr 4 & 6 & 3 } \right ), \quad N=\left (\array{ 2& 7 & 8\cr 4 & 2 & 6 \cr 5 & 7 & 5 } \right ) \]
\(K\) and \(M\)
\(K\), \(L\) and \(M\)
\(K\), \(L\) and \(N\)
The main diagonals of any two matrices differ.

2000017201

Level: 
A
Which of the given matrices is of order \(3\) and has an entry of \(2\) at the position \((3,2)\)?
\[ \left (\array{ 1& 2 & 3\cr 4 & 3 & 4 \cr 3 & 2 & 1 } \right ) \]
\[ \left (\array{ 1& 2 & 3\cr 4 & 3 & 2 \cr 3 & 4 & 1 } \right ) \]
\[ \left (\array{ 1& 2 & 3\cr 4 & 3 & 2 \cr 3 & 2 & 2 \cr 1 & 2 & 3} \right ) \]
\[ \left (\array{ 1& 2 \cr 3 & 4 \cr 3 & 2 } \right ) \]