complex numbers and 2x2 matrices
44923
Show that matrix under addition is isomorphic with the group of complex numbers under addition
26501
Proof using complex numbers
113907
All nilpotent $2\times 2$ matrices
33955
Geometric series of matrices
11857
$A$ be a complex $3\times 3$ matrix such that $A^3=-I$
79425
Prove the direct product of nonzero complex numbers under multiplication.
143689
Real $2\times 2$ matrix $X$ such that $X^2 + 2X= -5I$
29160
How can one convert rational matrices into integer ones?
108012
A matrix $M$ that commutes with any matrix is of the form $M=\alpha I$
152102
Prove that for every complex $2$x$2$ matrix $A$, there exists a matrix $X$ such that $X^3=A^2$.
32064
Zero-dimensional matrices
18145
Diagonalizable matrices with complex values are dense in set of $n\times n$ complex matrices.
130799
Matrix of rank 1; show that $A^2=cA$ for some scalar $c$.
145980
For every matrix $A\in M_{2}( \mathbb{C}) $ there's  $X\in M_{2}( \mathbb{C})$ such that $X^2=A$?
13794
$|z_{1} + z_{2}| = |z_{1} - z_{2}| \implies z_{1}/z_{2}$ is Imaginary
87136
All matrices which commute with all $2\times 2$ matrices
38550
2x2 matrices with sum of diagonal entries equal zero